ELMS 

ELECTRIC 8 
HYDRAULIC 



(5/ieir 

CONSTRUCTION 
CARESOPERATION 




THE LIBRARY 

OF 

THE UNIVERSITY 
OF CALIFORNIA 

LOS ANGELES 

GIFT OF 

John S.Prell 




ELEVATOES 
HYDRAULIC%ELECTEIC 



A Complete Hand Book containing Full 
Descriptions and Illustrations of the Mech- 
anism of All the Modern Types of Electric 
and Hydraulic Elevators : : : 

ALSO 



INSTRUCTIONS REGARDING THEIR CARE AND 

OPERATION THE DANGER INCURRED BY 

CARELESS HANDLING IS CLEARLY SET 

FORTH-A SERIES OF QUESTIONS 

AND ANSWERS FOLLOWS. 

Designed for the Use of 
Engineers and Operators 

BY 

CALVIN F. SWINGLE 

Author of "Encyclopedia of Engineering," "Twentieth Century Hand 

Book for Engineers and Electricians," "Examination 

Questions for Marine and Stationary Engineers." 




CHICAGO 

FREDERICK J. DRAKE & COMPANY 

PUBLISHERS 



COPYRIGHT 1910 

BY 
FREDERICK J. DRAKE & Co. 



INTRODUCTION 



Library 



sr 



Literature treating upon the subject of Elevators, either 
electric or hydraulic is extremely scarce. Even the manu- 
facturers themselves appear to be chary about issuing cir- 
cular matter descriptive of the various devices and appar- 
ratus that they build for the propulsion of Elevators. It 
is therefore with a view of assisting the engineer who is 
responsible for their care and safe condition, and the opera- 
tors whose duties are to handle elevators, that this little 
volume is sent forth. A study of its contents cannot fail 
to be of the greatest benefit to those interested, for the rea- 
son that the principles involved in the construction and 
operation of the various types of elevators are clearly set 
forth, and explained in language at once explicit, and to 
the point. Special efforts have been put forth to make the 
book a valuable guide and helper to elevator men. 

Each type of elevator is clearly illustrated in detail, and 
the action of the working parts so plainly described that a 
man does not require to be an expert in such matters in 
order to comprehend their principles. A complete cate- 
chism of Questions and Answers follows at the close of the 
subject matter. 

This catechism includes not only a thorough drill regard- 
ing the construction and care of elevators and their neces- 
sary adjuncts, but it also treats upon correct, and incor- 
rect, safe, and unsafe methods to be pursued in their opera- 

tion 733217 



Uf 6r Mechanical Engine^ 

SAN FRANCISCO CAL. . 

Elevators Electric and Hydraulic 

As the majority of stationary engineers, especially in 
large cities and towns, have more or less to do with ele- 
vators, either electric or hydraulic, the author deems it 
fitting and proper that a section should be devoted to this 
subject. 

Therefore, the construction and operation of electric and 
hydraulic elevators will be taken up in order, and although 
the subject-matter will have to be somewhat condensed for 
want of space, still the leading types, including the numer- 
ous improvements which have been developed during the 
past ten years will be illustrated, and the mechanism de- 
scribed. 



OTIS TRACTION ELEVATOR. 

Tn the Otis traction elevator the working parts have been 
reduced to the simplest possible elements. The elevator 
engine, a view of which is presented in Fig. 380, consists 
essentially of a motor traction driving sheave, and a brake 
pulley, the latter enclosed with a pair of powerful spring 
actuated, electrically released brake shoes, all compactly 
grouped, and mounted on a heavy iron bed plate. 

Instead of the high speed motor used with the geared 
electric elevator, a, slow speed shunt-wound motor designed 
especially for the service is used. The armature shaft 
which is of high tensile steel, of unusually large diameter 
serves merely as a support for the load, and on it are 
mounted the brake pulley and the traction driving sheave. 

11 



12 Steam Engineering 

The actual drive from the armature to the sheave is effect- 
ed through the engagement of projecting arms on each, 
cushioned by rubber buffers, thus entirely eliminating all 
tortional strains to the shaft, and the use of keys. In this 
machine all intermediate gearing between motor and driv- 
ing member is dispensed with, by the use of the slow speed 
motor, and the result is, that the starting, accelerating, re- 
tarding and stopping events are each, and all, remarkably 
even and quiet. 




FIG. 380 

OTIS TRACTION ELEVATOR 

The driving cables, from one end of which the car is 
supported, while to the other end the counterweight is 
attached, pass partially around the traction driving sheave 
in lieu of a drum, continuing under an idler leading sheave, 
thence again around the driving sheave, thereby forming a 
complete loop around these two sheaves, which arrange- 
ment results in the necessary tractive effort for lifting the 
car. One of the striking advantages resulting from this 



Otis Traction Elevator 13 

arrangement of cables, and the method of driving the same 
is the decrease in traction which follows the striking on the 
bottom of the shaft of either the car or the counterweight, 
and the consequent minimizing of the lifting power of the 
machine, until normal conditions are resumed. Inasmuch 
as in any properly constructed elevator the parts are so 
arranged that the member (car or counterweight) which 
is at the bottom of the shaft must strike and come to rest 
before the other member can possibly come in contact with 
the overhead work, it will readily be seen that the above 
mentioned decrease in tractive effort is a valuable, and 
effective safety feature inherent in this type of elevator. 

The controller is so designed in connection with the 
motor, that the initial retarding of the car in bringing the 
same to stop is independent of the brake, the latter being 
requisitioned to bring the car to a final positive stop and to 
hold it at the landings. 

The motor is also governed in such a way, electrically, as 
to prevent its attaining any excessive speed with the car no 
matter what the load in same may be. 

In designing the controlling equipment, one of the fea- 
tures demanding greatest consideration, in view of the very 
high speed at which the cars run, is the automatic retard- 
ing of their speed and the final positive stopping of same, 
automatical!}', at the upper and lower terminals of travel. 
This result is very satisfactorily attained with the installa- 
tion, in the elevator hatchway, of two groups of switches 
located respectively at the top and bottom of the shaft, eacli 
switch in the series being opened one after another, as the 
car passes, resulting in a reduction of speed until the open- 
ing .of the final switch brings the car to a positive stop, 
applying the brake. This operation is entirely independent 



14 



Steam Engineering 



of the operator in the car and is effective even though the 
car operating device be left in the full speed position. 

Another feature of security of the greatest interest and 
importance is provided in the Otis Patented Oil Cushion 
Buffers. (See Fig. 381.) These are placed in the hoistway, 
one under the car and one under the counterweight, and 



' 




FIG. 381 

OTIS PATENTED SPRING RETURN OIL BUFFER 



are arranged to bring either the car or the counterweight to 
a positive stop, through the telescoping of the buffer this 
occurring at a carefully calculated rate of speed, which is 
regulated by the escape of oil from one chamber of the 
buffer to another. The buffers have been proven capable 
by test of bringing *, loaded car safely to rest from full 



Otis Traction Elevator 



18 



speed, and in this respect are unique among elevator safety 
features of comparatively low cost. 

The usual safety devices installed in connection with 
modern high grade apparatus are used with this type of 
elevator, including speed governors, wedge clamp safety 
devices for gripping the rails in case of the car attaining 
excessive speed, and potential switches. 



OTIS GEARED TRACTION ELEVATOR. 

The modern adaptation, in the Otis Traction Elevator, of 
the traction principle for elevator service which utilizes 
the patented feature of operating the car by means of driv- 




FIG. 382 

OTIS DIRECT CURRENT TRACTION MACHINE FOE OVERHEAD INSTAL- 
LATION 

ing the cables direct from the motor without the interven- 
tion of retarding rigging, showed so conclusively the merits 
of that principle that the question naturally arose as to the 



16 Steam Engineering 

feasibility of employing this method of drive in the low 
speed machines as well. The result was the introduction 
of what is commercially known as the Otis Geared Trac- 
tion Elevator which embodies many of the good points of 
its larger contemporary. 

It might be well to state here that the traction principle 
is neither new nor experimental, as is instanced by its use 
in the familiar type of carriage hoist, this being in reality 
a low duty hand power traction elevator driven by means 
of a hemp rope; also this method of drive has been em- 
ployed on dumb-waiters for some time. However, as ap- 
plied to the high speed passenger machines used in our tall 
office buildings, it must be referred to as a comparatively 
new and improved development of former types. 

The Geared Traction machine is similar in appearance 
to the standard drum machine, except that a multi-grooved 
driving sheave is mounted in place of the drum, and a non- 
vibrating idler leading sheave takes the place of the vibrat- 
ing sheave necessary on the drum type. The car and the 
counterbalance weight hang directly from the driving 
sheave one from either end of the cables in precisely the 
same manner as with the Otis Traction Elevator ; the neces- 
sary amount of traction being obtained by the extra turn 
resulting from passing around the idler sheave. 

The machines are built in two classes, double screw, and 
single screw, depending upon the duty required. 

The double screw machine is designed for the heavier 
duties, and the gearing consists of a right and left hand 
worm, see Fig. 383, accurately cut from a solid forging. 
This worm, coupled directly to the electric motor, runs 
submerged in oil and meshes with two large bronze gear 
wheels, which in turn mesh with each other. The effect of 
the three-point drive thus obtained, in conjunction with 



Three Point Drive 17 

the right and left hand thread, is the entire elimination of 
end thrust on the worm shaft a most desirable feature. 
The complete gear is fully protected in an oil tight iron 
case and is well lubricated in every part. 

To the forward gear wheel, that is the one furthest from 
the motor, there is bolted the iron buffer-neck, or what 
might be termed the driving spider. It is constructed in 
such a way that the use of keys is unnecessary to effect the 
drive, inasmuch, as the flange of the buffer-neck is bolted 
with through bolts directly to the bronze gear wheel near 




FIG. 383 
THREE POINT DBIVE 

its periphery, and by means of four extending arms on its 
opposite end engages with similar arms on the driving 
sheave. A mechanically strong and perfect drive is thus 
obtained. The shaft passing through the driving sheave 
and buffer-neck serves merely as a support for the moving 
loads and is subject to absolutely no tortional strains. In 
order to protect the gears and elevator car from possible 
vibrations, large rubber buffers are placed under slight 
compression between the arms of the sheave and those of 
the buffer-neck. 



18 Steam Engineering 

The machine is equipped with a mechanically applied, 
and electrically released double shoe brake. The shoes are 
applied against a pulley of ample diameter and width to 
dissipate any heat generated, and serves as a coupling be- 
tween the motor shaft and the worm shaft. 

The brake shoes are normally bearing against the pulley 
with a pressure corresponding to the compression of the 
two helical springs. When current is admitted to the 
solenoid brake magnet, and then only, the action of the 
springs for the time is overcome, so that the shoes are 
released.. It will be seen, therefore, that the brake will 
apply with full force should a failure of current occur; 
resulting in an immediate stop of the elevator. 

The motor is compound wound, and runs at about eight 
hundred revolutions per minute at full car speed and load. 
The series field is used only at starting to obtain a highly 
saturated field in the shortest possible time, and is then 
short-circuited, leaving the motor to run as a plain shunt 
wound type. 

In stopping, a comparatively low resistance field is 
thrown across the armature, providing a dynamic brake 
action and a gentle slowing down of the car, the mechanical 
brake being called upon only to effect the final stop and to 
hold the load at rest. Resistance in series with this "Extra 
Field," as it is called, is controlled by magnets which de- 
pend, in their operation, on the speed of the armature. 
It is therefore evident that the dynamic, or retarding effect 
of the field is proportional to the speed, and therefore to 
the load in the elevator car, hence good stops under all 
conditions are easily obtained. 

To meet the demands in districts where alternating cur- 
rent is in use, the same apparatus described is furnished 



Alternating Current Machine 



11) 



except that the direct current motor and controller give 
place to an alternating current motor and controller. 

The alternating current machines are made in two classes 
also, single and double screw. The cut, Fig. 384, repre- 
sents a double screw machine designed for basement in- 




FIG. 384 

OTIS ALTERNATING CURRENT DOUBLE SCREW TRACTION MACHINE 
Designed for Basement Installations 

stallations. The brake is slightly different in appearance 
but performs the same functions as does the direct current 
brake. 

The safeties used on the Otis Traction Elevators are 
found on the geared, traction elevators. The main differ- 
ence between the two machines being the ability to use on 



20 



Steam Engineering 



the latter a small high speed motor with gearing, instead 
of the large, slow speed and more expensive motor of the 
Otis Traction Elevator. 




Fig. 385 
MAGNET CONTROLLER 

Fig. 385 shows the Otis electric magnet controller, and 
Fig. 386 shows the standard oar switch. With this operating 
device the current is automatically and gradually admitted 
to the motor, enabling the operator to start and stop the 
car without shock or jar. This controlling device is con- 



Magnet Controller 21 

structed to secure the motor against damage by any over- 
load, or excess of current; these features are automatic in 
their operation, are independent of the operator in the 
car, and are designed to prevent more current being ad- 
mitted to the motor than is required to do the maximum 
work of the elevator. 




FIG. 36 
OTIS LEVER CAR SWITCH 

Electro magnets are employed throughout, thereby elim- 
inating the use of all rheostats, sliding contacts, or other 
easily deranged devices. The contacts and wearing parts 
in the controlling mechanism are of ample dimensions to 
meet the severe conditions, and exacting requirements of 
elevator operation and control, 

Careless Operation. The waste of power caused by the 
careless operation of electric elevators is well worth consid- 



22 Steam Engineering 

eration. The following timely suggestions are quoted from 
an article by C. M. Bipley in the September, 1909, issue of 
Power : 

"An electric passenger elevator driven by a 30-horse- 
power motor on a 220-volt circuit is generally fused for 150 
amperes. Assuming that it requires four seconds for the 
car to gain its maximum speed, and that electric service 
costs 10 cents per kilowatt-hour, the cost of merely start- 
ing the elevator will figure out as follows : 

150X220X4=132,000 watt-seconds; 
132,000^3600=36.6 watt-hours or 

0.0366 kilowatt hour; 

0.0366X10=0.366 cent, or over a third 

of a cent. 

"In a building with, let us say, one elevator, serving six 
floors continually for eight hours, this waste in power would 
be considerable if the operator had to make one unneces- 
sary start on each trip, or two unnecessary starts for each 
round trip. If this car made 84,000 round trips in a year, 
the power waste would cost over $60. And if this average 
held good in buildings with ten elevators instead of one, 
with 24-hour service instead of 8-hour service, and with 20 
stories instead of six stories, the loss would amount to 
something over $3,000. The wear and tear on switch con- 
tacts, controller contacts, controller magnets, commutator, 
armature, steel worm, bronze gear or gears, thrust plates, 
ball bearings, armature bearings, drum-shaft bearings, the 
car cables, the counterweight cables and the back-drum 
cables are all materially increased also by increased 
starting." 

Table 49 gives some interesting and instructive data 
regarding the starting and running current, fuse capacity, 
etc., of various sized motors for Otis elevators. 



Overhead Installation 




FIG. 387 

DOUBLE WORM AND GEAR ELECT KIC ELEVATOR, OVERHEAD INSTAL- 
LATION 



Steam Engineering 



-punoj 'anbaoj, 



lOWt-INN 



w eo w 



Basement Installation 




FIG. 388 

SINGLE WORM AND GEAB ELECTRIC ELEVATOB, BASEMENT INSTAL- 
LATION 



26 Steam Engineering- 

In addition to the waste of power caused by unnecessary 
starts, there is the tremendous strain to which the appar- 
atus and cables are subjected when the car is suddenly 
stopped on the down trip; there is also the liability of 
burning out armatures by hasty reversals. Most elevator 
controllers are designed now so that the current cannot be 
sent through the motor in the reverse direction until the 
armature has ceased revolving. But there are many con- 
trollers still in use which are not so equipped, and motors 
operated with such controllers can easily be damaged by 
suddenly reversing the car switch before the motor has 
stopped revolving. If an elevator operator reverses his 
switch to the "down" position before the motor has fully 
ceased rotating in the "up" direction, the effective voltage 
at the armature terminals will be practically the sum of 
the line voltage and the counter electro-motive force of the 
armature, instead of the difference between the line voltage 
and the counter electro-motive force, or almost twice the 
line voltage, with nothing to oppose it but the very low 
resistance of the armature winding and connections. This 
would result in a flow of an enormous current sufficient 
to burn up the armature in short order if the safety fuses 
did not melt promptly. 

HYDRAULIC ELEVATORS. 

The mechanism of a hydraulic elevator consists of a 
cylinder and piston, the piston being connected by one 
or more piston rods to a cross-head which carries the 
sheaves over which run the lifting cables from which 
the car is suspended. By means of suitable valves, and con- 
trolling mechanism operated from the car, water, under 
pressure from compression, or gravity tank systems, or 



Hydraulic Elevators 




FIG. 389 

from street mains where sufficient pressure is available, is 
caused to flow inio, and out of the cylinder, thus causing 



28 Steam Engineering 

the piston to move from one end of the cylinder to the 
other, and back again. This motion of the piston and 
cross-head to and fro imparts motion to the lifting cables 
which pass over sheaves at the top of the elevator hatchway, 
and which hold in suspension the car, thus moving it up 
or down, according as the water flows into or out of the 
water cylinder. 

The motion of the piston transmitted to the cable is 
multiplied to a greater or less degree, according to the 
design of the elevator, by being caused to pass over sheaves 
designed for that purpose. 

Thus the ratio of increase in speed may be anywhere 
from 2 to 1, to 12 to 1, to meet the requirements due to the 
nature of the service, whether freight or passenger. The 
height of the building also controls in a large measure the 
speed, for instance in very tall buildings the elevators may 
be geared as high as 12 to 1. 

The cylinders of hydraulic elevators are made either ver- 
tical, or horizontal depending upon local conditions. If 
the floor space is restricted, vertical cylinders are used, 
but in cases where space above the basement floor for the 
accommodation of vertical machines cannot be easily ob- 
tained, it is the usual practice to place horizontal cylin- 
ders in the basement. Vertical cylinders are usually geared 
three and four to one, although ratios of from two to one, 
up to six to one are quite common. 

Fig. 389 presents a view of a low pressure vertical cylin- 
der hydraulic elevator geared two to one. The cut shows 
the general arrangement of the mechanism, from base- 
ment to top sheave. This type of hydraulic elevator is 
operated by the movement of the hand rope n, which passes 
around a sheave at the side of the valve chamber, and 
moves the valve by means of a rack and pinion gear. 



Hydraulic Elevators 29 

Rope n then passes under two small sheaves at the bottom 
of the elevator hatchway, and from thence up to the top 
of the hatchway, and over another small sheave. One side 
of this hand rope passes through the car, and by pulling 
this side up the operator causes the car to descend, and by 
pulling the rope down the car will ascend. Near the top, 
and bottom of the hatchway two balls m and m' are placed 
upon the hand rope. They are large enough to prevent 
their passing through the openings in the floor, and roof 
of the car through which the hand rope passes. When the 
car ascending strikes the upper ball m, the latter is carried 
up with the car, thus pulling up the hand rope, and moving 
the control valve back to the stop position. Should the car 
fail to stop, the valve will be carried past the stop position, 
which will connect both ends of the cylinder, and the car 
will start to descend. If, however, every part is properly 
adjusted, this reversal of the motion of the car cannot 
occur, because under such conditions, the car will stop 
when the valve is closed. If by any mishap the car should 
run away, and go beyond the normal limit of its travel, the 
control valve would be slightly opened in the opposite direc- 
tion, just sufficient to develop a retarding force and thus 
stop the car. The action is the same when the car approaches 
the bottom, as it will then strike ball m', which will be 
carried down, thereby closing the operating valve. Balls 
m and m' are in fact automatic top and bottom limit stops, 
and constitute one of the most valuable safety devices with 
which elevators are equipped. 

Another valuable device is the speed limit, which usually 
consists of stops mounted at some convenient point in the 
hatchway, and set above and below balls m and m', so as to 
limit the distance through which the latter can be moved. 



30 



Steam Engineering 



In some cases additional stop balls are used, on account of 
its not being convenient to place stops to act directly upon 
m and m'. The positions of these stops which limit the 
amount of opening of the valve, are determined experi- 




FIG. 390 



mentally when the elevator is installed. The movement of 
the car is kept steady by guides M, M, Fig. 389. In the 
construction shown in Fig. 389 these guides are made of 
hard wood. At the top of the car adjustible shoes are 



Safety Devices 31 

provided, which slide freely against the guides. At the 
bottom the car is guided by jaws formed in a safety device, 
or "safety" as it is termed. It is made of hard wood blocks, 
the dimensions varying from 4 inches thick by 11 inches 
wide in the smaller sizes, to 5 in. x 15 in. in the larger 
sizes. The jaws of this safety are reinforced with massive 
iron castings, and on one side are provided with a wedge 
that can be adjusted in position by means of screws, and on 




FIG. 391 

the opposite side with another wedge that can be forced 
between the guide and the jaw to stop the car if one of the 
lifting ropes breaks, or the car attains an excessive velocity 
from any cause. 

By reference to Fig. 390, and also to Fig. 391, which 
shows one end of the safety device, its construction and 
operation will be clearly understood. 

In Fig. 391 the governor rope rod L is shown only in 
the end elevation. Referring to Fig. 390 it will be seen that 



33 Steam Engineering 

the two lifting ropes that run down to either side of the 
car are connected with the ends of a rocking lever C. This 
lever C, as shown in Fig. 391, is pivoted at D', hence if 
either one of the lifting ropes breaks, the end of the lever 
it is attached to will drop down. The shaft II which 
extends under the car from one side to the other, carries at 
its ends a lever L' which, when raised lifts the wedge N 
and forces it into the space between the guide M and the 
side of the jaw of the safety plank. Whichever way the 
lever C may be tilted by the breaking of one of the lifting 
ropes, it will rotate shaft H and lever L' in the proper 
direction to throw up wedges N, thereby locking the car 
against the stationary guides M. 

The levers on shaft H are sufficiently long to strike the 
guides M, when raised high enough, and are sharp at the 
ends so that they will cut into the guides. 

It might be thought that if the wedge N is only raised 
far enough to catch in the space between the guide M and 
the safety-plank jaw it would be forced upward so tightly 
as to stop the car without further assistance. This would 
be the case if the wedge had a sufficiently long taper, but 
if it were so proportioned, it would require an enormously 
strong jaw to resist the bursting strain ; moreover, the car 
would be so tightly wedged that it would require a greater 
force to release it than could be easily obtained. 

With the wedges of the proportions used, it is necessary 
to make the lever that lifts the wedge so that it will dig 
into the guide, and as the car moves down through, say, a 
foot or two in coming to a stop, the lever shaves the side 
of the guide, thereby not only forcing the wedge tighter 
against the guide, but producing an additional retarding 
force. When a car is caught by the safety, all that is neces- 



Safety Devices 



33 



eary to release it is to start in the upward direction, and the 
force exerted by the lifting cylinder is enough to overcome 
the friction of the wedges against the guides. 

In the foregoing it is shown how this safely acts, provid- 
ing one of the ropes breaks. Elevator cars, however, seldom 
drop when one of the ropes breaks, but frequently attain 




FIG. 392 



a very high velocity when the ropes do not break, and on 
that account it is necessary to arrange the safety so that 
it will act when the speed reaches a certain stage regard- 
less of the cause of increased velocity. This is accom- 
plished by means of the Otis safety governor, shown 
mounted on one of the overhead beams in Fig. 389, and in 
detail in Fig. 392. This device is driven by the rope L, 



34 Steam Engineering 

which is made fast to one end of lever G' as shown in 
Fig. 389. The spring that holds G' is strong enough to keep 
the lever in its normal position and rotate the safety gov- 
ernor at a velocity proportional to the speed of the car. 
Eeferring to Fig. 392 it will be seen that the governor may 
be adjusted by means of the spring on the spindle, to act at 
any desired velocity. The governor driving rope passes 
through the clamping jaws H H', and when the governor 
speed becomes great enough to lift the rod Z and throw 
the jaws together, the rope will be clamped. Then, as the 
rope cannot move, the outer end of the lever G' on the 
safety plank will be held stationary as the car descends ; 
hence, the shaft H will be rotated, throwing the safety 
wedges N into action to stop the car. It is evident that 
the car can descend only as far as the upward movement of 
the end of lever G' and the compression of the spring on 
L will permit, before the rope will be compelled to slide 
through the clamps H, H' of the governor. As the distance 
through which the spring can be compressed, plus the move- 
ment of the end of G' is only a few inches, it is evident 
that unless the car is stopped very short, the rope L must 
break if it cannot slide through clamps H, H'. The dis- 
tance in which the car will stop is always considerably more 
than the compression of the spring plus the movement of 
the end of G'; hence, while it is necessary for H H' to 
clamp the rope tight enough to move G', the pressure must 
not be so great as to prevent the rope from slipping. For 
the same reason, in order to make the safety governor 
reliable it is necessary that the operating rope shall be in 
just as good condition as the elevator lifting ropes. The 
failure to inspect this rope properly, and make sure that 
it is at all times in perfect condition has been a prolific 
cause of accidents. 



Safety Devices 



35 




The jaws of the safety plank and the wedge N should be 
kept clean and in proper adjustment at all times. As the 



36 titeam Engineering 

guides M have to be kept well lubricated, it can be easily 
seen that if the safety jaws are neglected they will soon 
become clogged with a mixture of grease and dust, and this 
may give a considerable trouble by causing the wedge to 
stick to the side of the guide and thus go into action when 
everything else is running properly. The wedge N, and 
the adjusting wedge on the opposite side of the guide, will 
gradually wear away. For this reason the latter should 
be set up as often as required to keep the proper amount 
of clearance between the guide, and the safety jaw. If the 
clearance is too great, the wedge N is liable to not catch 
firmly when called into action, and if the clearance is too 
small, the safety is liable to act when not required. 

The operating valve shown in Fig. 389 is the same in 
principle as the one shown in section in Fig. 393, but it 
has several details of construction not shown in the latter. 
Its design is shown more in detail in Fig. 394, which is a 
sectional elevation of the valve, and casing. The casing 
is made in three parts marked 7, 8 and 9. Part 7 forms 
the top, and provides a dome, into which the rack 6 on the 
end of the valve rod can rise as the valve is lifted by the 
rotation of the pinion on the end of the shaft A. This 
shaft carries at its outer end the hand rope sheave shown 
at the side of the valve in Fig. 389. The parts 7 and 8 are 
divided at the center of the shaft A, and form a bearing 
for the latter. 

The lower part 9 which is the valve casing proper, has 
ports 10 and 11 for connection with the lower end of the 
circulating pipe, and the lower end of the cylinder, in the 
manner indicated in Fig. 393. That portion into which 
the circulating pipe is connected forms a separate casting 
in Fig. 389, and the casing 9 is bolted to it. Port 12 in 
part 9 of the valve casing is for the purpose of connecting 



Safety Devices 



37 




FIG. 394 



38 Steam Engineering 

with the pressure-water supply if for any reason it is not 
desired to have this connection made in the circulating 
pipe. The valve casing is lined with brass tubing 4 and 3. 
Lining 4 is simply for the purpose of providing a smooth 
surface for the cup packing of V to slide against. Lining 
3 is provided for the purpose of making ports of sucli a 
character that the cup packings of V may be able to slide 
over them freely. 

If the ports were large openings, the packings could not 
pass over them, because on the up movement they would be 
caught by the edges of the ports. With the brass linings 
this trouble is overcome by perforating the brass with a 
large number of small holes, about one-quarter of an inch 
in diameter. The combined area of the holes is much 
larger than would be required in a single port, this increase 
in opening being provided so as to reduce the friction of 
the water running through the holes by reducing the 
velocity of flow. 

The pressure of the water tends to force the valve piston 
V up, and the other piston V down, and as both pistons 
are the same in diameter, the valve is balanced. Never- 
theless the force required to move the valve is considerable, 
owing to the friction of the cup packings, caused by the 
pressure of the water acting upon the entire surface of the 
leather in contact with the brass linings of the valve casing. 

On this account the pinion on the shaft A, through which 
the valve is moved, is made very small, while the hand rope 
sheave is large about 20 inches in diameter so that while 
the valve travels a few inches in either direction the hand 
rope has to be pulled through a distance of from two to 
four feet, according to the size of the valve and the speed nf 
car. For high car speeds the hand rope movement is in- 
creased, so that the automatic top and bottom stops may 



Operating Valve 39 

be able to arrest the movement of tbe car without making 
the stop abruptly. Reference to Fig. 394 will show that 
the lower head that clamps packing 2 is made tapering. 
This is done in order to prevent too quick a closure of the 
outlet from the lower end of the cylinder when the valve is 
moved down to stop the car on the up trip; otherwise the 
stop would be too abrupt. Even with this precaution it 
is possible for the operator to close the valve too quickly; 
therefore a check valve is inserted in the passage connect- 
ing the valve casing with the cylinder. 

This check is directly under the lower end of the circu- 
lating pipe, so that if the operator closes the valve too sud- 
denly the descent of the piston within the cylinder will not 
be arrested instantly, but the piston will slowly continue 
its movement and gradually force the water under it to 
pass through the relief check valve, into the circulating 
pipe, and thus into the top end of the cylinder. If the 
operator moves the hand rope so quickly on the down trip 
as to produce a violent stop, the piston will continue to rise 
in the cylinder, and the water above it which cannot pass 
to the lower end of the cylinder on account of the valve 
being closed, will be forced back through the inlet pipe I to 
the pressure tank. In this case, as no water can pass into 
the lower end of the cylinder, the continued upward move- 
ment of the piston causes it to leave the water, and thus 
a vacuum is formed underneath it. 

This vacuum together with the tank pressure on top of 
the piston soon arrests the movement of the car, but the 
stop is not so sudden. One objection to having the con- 
nection from cylinder to pressure tank through the inlet 
pipe I is, that if for any reason the pressure in the tank- 
should drop to zero, owing to the starting of a bad leak, 
the water in the top end of the cylinder could immediately 



40 



Steant Engineering 




FIG. 395 



Operating Valve 41 

run out with such freedom that if the car should happen 
to be at, or near the top of the hatch' way it would attain a 
dangerous speed by the time it reached the bottom. But 
by locating the pressure tank on the roof of the building 
the danger from this source is obviated, for the reason that 
the flow of the water from the cylinder would then be 
against a pressure due to the elevation of the tank, and to 
this may be added the pressure of the atmosphere, for the 
reason that the valve being closed, no water can pass into 
the lower end of the cylinder, and as the piston moves up, 
a vacuum is formed under it thus tending to retard its 
motion. 

The result is that the combined pressures are sufficient 
to hold the car within safe speed limits. When the pressure 
tank is located in the basement, the danger above referred 
to is avoided by using a valve of the type shown in Figs. 
395 and 396. Fig. 395 shows the casing, and Fig. 396 the 
valve. 

The difference between this valve and that of Fig. 394 
is that it is provided with an additional piston V", see Fig. 
396, which is called the throttle valve. When this valve 
is used, the inlet pipe from the pressure tank is attached 
to the port 12. When the elevator is stopped, the throttle 
valve V" is directly opposite the port 12, and thus obstructs 
the flow of water from the port 10. It will be seen that a 
groove is turned in V" at the center line. In addition the 
valve is not made a perfect fit in the casing, and the clear- 
ance thus afforded is sufficient to permit water to pass by 
in as large an amount as may be required to prevent a too 
sudden stoppage of the car should the operator close the 
valve too quickly. Another advantage is, that in case the 
tank pressure should fail, the flow of water past this clear- 



Steam Engineering 



FIG. 396 

ance is retarded sufficiently to prevent a dangerous s 
in the descent of the car. 



Operating Valve 



43 



When the valve is moved in either direction to set the 
car in motion, water passes from port 12 to port 10 through 
side ports 14. A portion of this water passes directly from 
12 to 14, and the other portion passes around the upper 
lining 4, through circular passages 13, and thence down 




FIG. 397 

into 14, as indicated by the arrows. In this way sufficient 
opening around the throttle valve is afforded even when 
the port of the operating valve piston V is only slightly 
open. The passages 13 and the connection between the 
ports 14 and 10 are not easily made out from Fig. 395, but 



44 Steam Engineering 

the arrows indicate the course of the water, and these make 
the construction more easily understood. Fig. 397 which is 
a section through the passages 13, taken at right angles 
to Fig. 395 will serve to illustrate more fully the construc- 
tion. 

The pistons used in vertical hydraulic elevators are made 
in several designs, some being arranged so as to be packed 
from the upper end, and others so as to be packed from the 
lower end. Fig. 397 shows one of the latest designs of pis- 
tons arranged to be packed from the lower end of the cylin- 
der, which appears to be the favorite type now. The draw- 
ing shows a section through the complete pistoti, with pack- 
ing in place, also a section of the cylinder C. 

Ordinary square packing is used, and this is held in 
position by a follower secured by six bolts. Fig. 398 shows 
the body of the piston only. The parts P and P" are made 
to fit the cylinder, but the intervening section is cut away 
on opposite sides, so as to afford space for the ends of the 
piston-rods and their fastening nuts. The top and bottom 
parts of the piston are connected by the pillars I and I. 

In packing these pistons it is necessary to be careful not 
to press the packing in too tight,- as there is danger of burst- 
ing the cylinder by so doing, and even if this much damage 
is not done, the friction caused by the excessive pressure 
may be so great as to prevent the car from attaining its 
full velocity. If a hard packing is used, and this is forced 
into place dry and very tight, the chances are that when it 
becomes well soaked it will expand enough to burst the 
cylinder. Bursting hydraulic-elevator cylinders is not a 
very rare occurrence, and when it does occur it is due to 
too great pressure of the piston packing against the sides 
of the cylinder. 



Piston Packing 




Fio. 398 



46 Steam Engineering 

Referring to Fig. 389, it will be noticed that there are 
two piston rods, E. 

This construction was adopted in the early days of hy- 
draulic elevators partially to increase the safety of the 
apparatus, but principally to prevent the traveling sheave 
B from twisting around. The ropes tend to hold the sheave 
from twisting, but they will not prevent slight movements, 
while the double piston-rods will. Xow and for several 
years past, however, the frame of the traveling sheave has 
been made in the form of a crosshead running in stationary 
guides, thus effectually preventing any side movement of 
the sheave. With this construction the main benefit of the 
double piston-rods is additional safety; while it is possible 
for one rod to break or become loose, it is practically im- 
possible for both to give way at the same time. 

The arrangement of the cylinder C, the circulating pipe 
K, and the valve V, in Fig. 389, is the same as in the dia- 
gram Fig. 393, even the inlet I being similarly situated. 
The small pipe c is for the purpose of carrying off the drip 
from the upper side of the top cylinder head, ordinarily, 
and also for the purpose of draining the water from the 
upper end of the cylinder, in cases where it is necessary to 
run the piston to the top of the cylinder to renew or adjust 
the packing. Some cylinders are arranged to be packed 
from the upper end and others from the lower end, the 
latter design being the one generally used in modern ma- 
chines. As will be noticed, the pipe c connects at the bot- 
tom of the cylinder with other pipes that connect to the 
valve chest and the lower end of the cylinder. All these 
pipes are either to carry off the drip or to draw water from 
the various parts of the cylinder and valve chest when 
desired. Globe valves are placed in the drainage pipes so 
as to keep them closed normally. 



Operating Devices 47 

Counterbalance. Generally a portion of the counter- 
balance is placed on top of the piston, so that in such ma- 
chines the counterbalance weight is divided into three parts, 
one being within the cylinder, one in the traveling sheave 
frame, and one constituting the independent counter- 
balance. 

Operating Devices. In order if possible to avoid the 
uncertainty of operation in connection with the hand rope 
in high speed elevators, lever, and wheel operating devices 
have been developed, and to make these devices operative 
and reliable, the operating valves have been somewhat modi- 
fied in design. The main valve, controlling the flow of water 
into, and out of the cylinder, varies in diameter from 3 
inches in small machines, to 7 or more inches in the large 
sizes. Fig. 399 shows the lever device for operating, a 
modern high speed hydraulic elevator. The lever L is 
shown located in the car. The movement of this lever to 
one side or the other rocks the horizontal lever M, and this 
motion causes the sheave P mounted on the frame I to 
rotate through a small angle. The rotation of P is trans- 
mitted to P' through the rope k, and the rotation of P' 
actuates the valves in a manner that will be presently ex- 
plained. 

Ropes m m, n n pass around sheaves N N N N located at 
top and bottom of the elevator hatchway, as is clearly 
shown. The ends m m are fastened to the ends of the 
lever M but the sides n n are not connected with it, although 
in the illustration they look as if they were. The side n 
that runs up from the right-hand side N sheave at the bot- 
tom passes over the N" sheave at the left-hand side at the 
top of the elevator hatchway. These two N sheaves at the 
top are mounted upon a frame I which is arranged so as 
to hold the sheaves firmly in the horizontal position, but 



48 



Steam Engineering 





FIG. 399 



Operating Devices 49 

allows them to revolve freely around the studs upon which 
they are mounted. The frame I is suspended from a rope 
that passes over the two small sheaves resting on top of the 
overhead heams. The end of this rope extends downward, 
outside of the elevator hatchway, and has a weight sus- 
pended from it so as to hold the ropes m m, n n, with the 
proper tension. 

Upon the larger sheave P are mounted the lower N N 
sheaves. If the right-hand end of lever M is depressed, 
the right-hand loop formed by the rope n m will be low- 
ered, while the left side end will be raised, and as a conse- 
quence the right side lower N sheave will swing downward 
while the left side one will swing upward. Thus the rope 
k will be pulled with the upper side moving from left to 
right, and sheave P' will be rotated in the direction in 
which the hands of a clock move. 

This arrangement of ropes for transmitting the motion 
of lever L to sheave P' is called the running rope system. 
There is another way of accomplishing the result with sta- 
tionary ropes, the upper ends of these being attached to 
the upper frame I and the lower ends to the sides of sheave 
P, or to the ends of a lever secured to this sheave. In this 
arrangement the rope that is fastened to the right-hand 
side of sheave P is secured to the left side of the upper 
frame I. The sheaves N N N N are placed upon the ends 
of lever M and each rope passes over one sheave at one end, 
and under another sheave at the other end of M. This is 
the standing rope system. For both systems there are sev- 
eral modifications, but the results are the same in each 
case, viz., to transmit the motion of lever L to sheave P'. 

Valve v controls the flow of water into and out of the 
hydraulic cylinder. This valve is actuated by a piston T 
located in the enlarged portion of the valve chamber, and 



50 Steam Engineering 

which is larger in diameter than valve v; consequently if 
water under pressure is admitted to the space between T 
and v, the pressure of the water upon the larger area of 
piston T will cause it to move up, provided there is no 
pressure on its top side. If water under pressure is ad- 
mitted to both sides of piston T, it will be balanced and will 
exert no force to move the valve in either direction. Valve v 
will, however, have the pressure acting upon its upper side, 
while the only pressure acting against its lower side will be 
atmospheric pressure, or that of the tank into which the 
water is discharged. Consequently the valve will move 
downward. Water is admitted to the space above piston 
T through a small pilot valve at h which is connected with 
the pressure pipe through pipe g, while pipe f connects it 
with the space above T. 

When the car is at rest, pilot valve h is in a position to 
close the ports connected with pipes g and f, and also pre- 
vents the escape of water into the larger pipe connecting 
the lower end of the pilot valve chamber with the main 
discharge pipe. Under these conditions, the water in the 
main valve chamber above piston T cannot escape unless 
valve h leaks. When sheave P' is rotated in a clockwise 
direction, the crank on the end of the shaft will draw down 
the connecting rod j, and as valve h can move much easier 
than main valve v and piston T the latter will remain 
stationary, while h will be depressed. This movement of 
h will uncover the ports connecting with pipes g and f, thus 
establishing a through connection between the pressure pipe 
and the space above T and the latter will be forced down- 
ward, carrying with it throttle valve V which will uncover 
the port connecting with pipe G, and also move the main 
valve v far enough down to uncover the upper edge of the 
port connecting with the lower end of the cylinder, thus 



Operating Devices 51 

opening a communication between the two ends of the 
main cylinder. Under -these conditions the weight of the 
elevator car which acts to pull piston F upward will set 
the latter in motion, and the water in the upper end of the 
cylinder E will be forced down through pipe G and 
through the valve chamber, around valve V into the lower 
end of the cylinder. The pipe G is called a circulating 
pipe, as one of its objects is to provide a path through 
which the water may circulate between the top and the 
bottom of the cylinder E. 

As the action just explained takes place when the ele- 
vator car descends, it will be seen that, for the down trip, 
no water is drawn from the pressure tank. To run the 
car upward, the sheave P' is rotated counter clockwise by 
swinging the car lever L in the opposite direction. When 
P' is so rotated, the crank on the end of the shaft will push 
connecting rod j upward, and thus pull on rod i and 
thereby lift the pilot valve h. The upward movement of 
h uncovers the port that connects with pipe f, but keeps 
that connecting with pipe g closed, so that the water con- 
fined in the valve chamber above T can now escape through 
pipe f, and the lower end of the pilot valve chamber into 
the discharge pipe. In this way the pressure acting on 
the top side of T is removed, and the pressure acting 
on the bottom side forces the valves up, owing, as has been 
already explained, to the difference in area between T and 
valve v. The upward movement of valve v opens communi- 
cation between the port running to the lower end of the 
hydraulic cylinder, and the discharge pipe, thus permitting 
the water in the lower end of the cylinder to escape through 
the discharge pipe. This upward movement of the valves 
also raises throttle valve V and allows the water in the 
pressure pipe free access to the port connecting with pipe 



52 Steam Engineering 

G, thus admitting a new supply of water under pressure 
to the space above the piston in the hydraulic cylinder. 
Under these conditions the water acting upon the top side 
of piston F in conjunction with the vacuum formed under 
the piston by the escape of the water into the discharge 
pipe, provides the force that depresses the piston and 
thereby lifts the car. 

Upon the rate of flow with which the water can enter, 
or pass out of the cylinder will depend the velocity with 
which the piston will move, and this rate of flow is evidently 
dependent upon the extent to which the valves are opened. 
If the operator in the car desires to run at a slow speed, 
he moves lever L a short distance from the central posi- 
tion; for a higher speed, he moves it further from the 
center, and for the highest velocity, he moves it as far 
as it will go. 

Now suppose L is moved a short distance only, then 
sheave P will be rotated through a short angle, imparting 
a correspondingly small movement to connecting rod j. 
Suppose j is depressed, thus opening the connection be- 
tween pipes g and f water will begin to flow into the 
space above T as soon as pilot valve h moves down far 
enough to uncover the ports connecting with pipes g and 
f and draw down the end S of lever Q. As j will now 
be stationary, it will act as a fulcrum, and R will be 
lifted. This movement will continue until pilot valve h 
is raised sufficiently to cover the ports connecting with 
pipes g and f, which will stop the flow of water into the 
space above T. It will thus be seen that, after pilot valve 
h has been moved by the rotation of the sheave P', main 
valve v, and piston T also begin to move, and as they 
move, the pilot valve is returned to stop position. If pilot 
valve h is moved but a short distance from stop position, 



Operating Devices 53 

piston T and valve v will have a correspondingly short 
distance to move to return the pilot valve to stop position. 
The amount of opening given to pilot valve h depends upon 
the distance the car lever L is moved. If for a short dis- 
tance, the opening will be but a small fraction of its travel, 
and the main valve will open a correspondingly short dis- 
tance, and vice versa. As water is practically incompres- 
sible, it is apparent that if lever L be too quickly moved 
to the central position when the car is moving at a high 
rate of speed, the motion will be arrested with a violent 
jerk. In order to prevent such action, means are provided 
whereby the water may find an outlet, if the valve is closed 
too suddenly. If the sudden stop occurs on the downward 
trip of the car, which is the up-stroke of piston F, the 
water will leak by the throttle valve V and flow back into 
the pressure pipe, and will continue to flow until the car 
has come to a stop. 

If the throttle valve Y were not provided, the water 
would escape too freely, back into the pressure pipe, and 
as a result the car could not be stopped in a very short 
distance; hence, the object of valve V is to provide means 
to prevent a too sudden stop of the car on the down trip, 
and at the same time not to permit the car to run farther 
than is necessary to make a gradual stop. Valve V is 
not water-tight, as has already been explained (see Fig. 
396), and its throttling action begins gradually. 

Should the car be stopped too suddenly on the up-trip, 
the water in the lower end of cylinder E will be forced 
through valve d at the bottom of pipe G, and the mo- 
mentum of the moving parts will be expended in com- 
pressing the spring that holds valve d to its seat. Fig. 399 
has been reduced in length, but it shows in detail all of 
the mechanism of a modern type vertical cylinder hy- 



Steam Engineering 




FIG. 400 



Cylinders 55 

draulic elevator, with running rope or standing rope con- 
trol. Other methods of control besides those already de- 
scribed are in use, mainly in private dwellings and other 
places where an operator is not employed. These consist 
of magnetic controllers for operating the pilot valve by 
means of push buttons, the magnets being operated by 
current from the incandescent light circuit, or if such a 
circuit is not available, the current is derived from pri- 
mary, or storage batteries. 

Horizontal Cylinder. The principal difference between 
the vertical, and the horizontal cylinder types of hydraulic 
elevators lies in the fact that in the one type the cylinder 
stands in a vertical position, while in the other it is placed 
horizontally. The principles governing the operation of the 
valve mechanism are practically the same in both cases, 
outside of a few details which will be explained. Fig. 400 
shows the general arrangement of a horizontal cylinder 
hydraulic elevator, including pump and pressure tank. 
The type here illustrated and described is the Crane push- 
ing type elevator, there being two distinct classes of hori- 
zontal hydraulic elevators, viz., the pushing and pulling 
types. Referring to Fig. 400, the stationary sheaves and 
rear end of the cylinder will be seen close to the hatch- 
way. The main valve which controls the admission and 
release of the water to and from the cylinder is located 
at K, and is automatically operated by the movement of 
the pilot valve L, the latter being actuated by the rocking 
of shaft M, which is done by means of rods m m con- 
nected with a running rope system operated by the lever 
in the car. An automatic stop valve is located at R simi- 
lar in design to that described in connection with vertical 
cylinder machines. This valve is actuated by the median- 



56 



Steam Engineering 



ism at N, which is set in motion by the movement of the 
crosshead. 

Figs. 401, 402 and 403 show the apparatus in detail. 




FIG. 401 



In Fig. 401, which is a side elevation, it will be seen that 
if lever S is moved in either direction, the rods m m will 




FIG. 402 

cause shaft M to rock, thus moving the pilot valve by 
means of valve rod I/. Moving the pilot valve will either 




FIG. 403 

open or close main valve K, which will allow the water to 
flow into, or out of the cylinder, depending upon what 
direction lever S is moved. 



Cylinders 57 

If the operator fails to return lever S to stop position 
when the car reaches the top of the hatchway, the frame 
N will be carried to the right by the motion of the cross - 
head, and the projecting arm D, Fig. 302, will strike 
the stop mounted on rod D" connected to the end of the 
frame. This movement of N will cause a roller at n' to 
strike lever o', which will move to the right, and pull 
rod Q with it, and this action will close stop-valve E, 
which will stop the flow of water into the cylinder, and 
the car will come to a stop. 

Should the car be descending, the main piston will be 
moving to the left, and if lever S is not returned to stop 
position at the proper time, the automatic stop will act in 
precisely the same way, except that frame N will be moved 
to the left instead of to the right. 

Eeferring to Fig. 403, which is a sectional elevation of 
the cylinder, piston, sheaves and connecting parts, it will 
be seen that there is a rubber ring around the piston end 
of the plunger E, and a similar ring in the crosshead D. 
A strong buffer frame I is attached to front cylinder head 
G. The function of these parts is to act as cushions in 
case the car travels past its normal position at either end. 
These parts should be adjusted so as to prevent the car, or 
counterbalance weight from striking the overhead beams 
in case the automatic stop valve fails to act. 

Pulling Type. Fig. 404 shows a view of a pulling type 
of horizontal cylinder hydraulic elevator. This machine is 
made by the Whittier Machine Company, and its action 
is as follows : G is the main operating valve, and the pilot 
valve is located directly above it at J. The automatic stop 
valve is at H, and is actuated by stop balls N mounted on 
rope L. These stop balls are moved by coming in contact 
with an arm attached to the crosshead, which also carries 



58 



Steam Engineering 




FIG. 404 
THE WHITTIER PULLING MACHINE 



Whittier Hydraulic Elevator 



59 



the traveling sheaves D, and shoes E on the crosshead 
slide within the side guides. 

The weight P suspended from the chain that travels 
between two small guide sheaves located just below the 
valve casing, is for the purpose of bringing the automatic 




FIG. 405 

stop valve to central position as soon as the piston moves 
away from either end of the cylinder, The shackle bolts 
for the ropes are shown at Q. 

The main and the pilot valves of the Whittier machine 
are shown in detail in Figs. 405 and 406, the first being a 




o Cylinder Fran Cj Under 



FIG. 406 

plan view and the second a sectional side elevation. Re- 
ferring to Fig. 405, it will be seen that the operating lever 
K is pivoted at the point F, so that when actuated by the 
operating ropes AA' it imparts an end movement to the 
pilot valve rod C. The ropes AA' are connected with the 



60 Steam Engineering 

operating lever in the car by either a running, or a stand- 
ing-rope arangement identical with those used for vertical- 
cylinder elevators. 

In Fig. 406 the pilot valve rod C is shown connected 
with the top end of lever D, the latter being pivoted at G. 
The part B, which holds the pivot G is actuated by the 
lever K. The supply pipe is connected with the right-hand 
end of the pilot-valve chamber through the pipe E. If the 
rod C is moved to the left, high-pressure water will pass 
through the pilot valve to the end I of the main valve and 
force the latter to the left, thereby connecting the cylinder 
with the discharge pipe, when the water will run out and 
the elevator car descend. The forward movement of the 




FIG. 407 

main valve will carry the lower end of the lever D to the 
left and the upper end to the right, until the pilot valve 
is returned to the closed position. If the pilot-valve rod 
C is moved to the right, the end I of the main valve 
will be connected with the discharge and the water will 
escape, then the pressure acting on the piston L will force 
the valves to the right and connect the supply pipe with 
the cylinder, which will fill with water from the pressure 
tank and the car will be forced upward. The movement 
of the. main valve to the right will carry the lower end of 
the lever D in the same direction and the upper end to 
the left, and return the pilot valve to the central position. 



Double-Decked Machine 61 

The pilot valve shown in Fig. 406 is provided with 
stuffing-boxes at each end to insure tight joints with the 
valve- rod, but this construction is not used in all the 
Whittier elevators; in some of them the pilot valve is 
made as shown in Fig. 407, where the escape of water at 
the ends is prevented by the use of cup packings. Tho 
pressure water enters through the port A, the discharge 
being through the port B; consequently, the cups are set 
so as to oppose the pressure which is exerted in both di- 
rections from the port A. 

Another design of the pulling-type elevator is presented 
in Fig?. 408, 409 and 410. This is called a "double-decked'-' 
machine, and is made by Morse, Williams & Co., of Phila- 
delphia. Why it is called double-decked can be understood 
from Fig. 408, which is a side elevation and shows two ma- 
chines placed one over the other. In buildings where floor 
space is limited, this construction is often adopted, in some 
cases three and four machines being installed one over an- 
other. Fig. 409 is a top view of Fig. 408, and Fig. 410 
is an end view seen from the right side. In these machine? 
there is but one piston rod, as at B., Fig. 408. The 
crosshead is similar to that in the Whittier machine, except 
that the sides of the end bars are square with the side 
frame's, instead of in line with the traveling-sheave shaft, 
as at J, Fig. 410. The guides F are set so that the 
crosshead shoes a, slide on top of the upper flange, not 
between the flanges. 

At the stationary-sheave end of the guides there are 
shorter guides TJ, which carry a shaft provided with small 
rollers b, the function of which is to support the ropes 
running over the upper sides of the sheaves. In Fig. 408 
the upper machine is shown with the traveling sheave? 
close to the stationary sheaves, caused by the car being at 



Steam Engineering 




the lower floor of the building. In this machine the sup- 
porting rollers b' are at the extreme right-hand end of 



Double-Decked Machine 63 

the guides U'. In the lower machine sheaves D are close 
to the cylinder, as they will be when the elevator car is 
at the top floor. In this case the supporting rollers b are 
at the extreme left-hand end of guides U and midway be- 







FIG. 410 

tween the sheaves D and E, the better to support the ropes 
at the central point. On the upper machine in Fig. 408 
a hook 1 mounted on a shaft carried by the guide shoes c' 
engages a piece e, secured to the part J', as shown in Fig. 
410, at the center. At one end of the shaft which carries 



64 Steam Engineering 

hook 1 there is a lever k. When the sheaves D' move to- 
ward the cylinder, the hook 1 being engaged with lever e, 
the supporting rollers b' are carried along with the hook 1 
until lever k reaches an inclined plane m, up which the 
rollers slide, causing the shaft to be rotated and hook 1 
to be pulled up out of the way of the lever e, the rollers 
being left in the position of those shown on the lower 
machine. The supporting roller shaft is kept in line, 
notwithstanding that it is carried along by the part e 
acting at the central point, by reason of the guide-shoes c 
being provided with grooves that fit over the guides IT, as 
clearly shown in Fig. 410. When the traveling sheaves 
move forward, the piece e engages hook 1 when the latter 
is reached, and the roller shaft is carried forward to the 
end of the guides, as shown at b. These supporting rollers 
relieve the ropes of considerable strain when the stroke is 
long, and the traveling sheaves are near the cylinder, but 
they are of little service in short-stroke machines. The 
movement of the roller shaft is equal to one-half the stroke 
of the machine. 

The Stop and Main Valves. In a machine of the pull- 
ing type the piston is forced toward the back end of the 
cylinder on the upward motion of the car. If the auto- 
matic stop-valve is properly adjusted, it will begin to close 
at the right time to stop the car even with the upper floor ; 
but if it is improperly adjusted, the car is likely to run 
into the overhead beams, therefore buffers g g, faced with 
rubber cushions h h, are provided. In the machine illus- 
trated in Fig. 408 the automatic stop-valve does not fit 
perfectly, and if the main valve is not closed when the 
car reaches the upper floor, the car will not stop but will 
slowly move upward until the crosshead brings up against 
the buffer cushions h h. On the downward trip, if the 



Stop and Main Valves 65 

main valve is. not closed when the car reaches the lower 
floor, the car will settle gradually until it rests on the 
bumpers, or the piston strikes the front cylinder head. 

In Fig. 408 the main valve is located at G and is 
actuated by a pinion at n which meshes with a rack in 
the neck-bearing n'. The automatic stop-valve is con- 
tained within the casing H and is actuated by a rod con- 
necting with a crank-pin on a crank-disk mounted on the 
shaft with the sprocket-wheel Q, Figs. 408 and 409. The 
sprocket-wheel Q is rotated by means of a sprocket 
mounted on the shaft with sprocket f, Fig. 409, which 
latter is operated by a chain, the ends of which are affixed 
to the ends of two square rods, the lower of which is shown 
at L. Another chain around the sprocket P is connected 
with the opposite ends of these two rods. To stop the 
movement of the piston, the stop-valve is actuated to the 
left. If the traveling sheave is moving toward the cylin- 
der the actuating bar E attached to the crosshead will 
strike the stop 1ST and move it to the left, which will set up 
a counter-clockwise rotation of the sheaves and Q, and 
this will move the crank-pin and the stop-valve to the 
left. If the traveling sheave is moving away from the cylin- 
der, the lower end of bar E will strike the stop N on the 
square rod L and, by carrying the latter to the right, ro- 
tate sheaves and Q counter-clockwise in the same direc- 
tion. The stops N are hook-shaped ; they slide over the 
side projections on bar E, Fig. 410, and lock with it, 
with the result that when the elevator is started on the 
return trip the movement of the crosshead carries the stop 
X with it, and the automatic stop-valve H is pulled open. 
When the elevator is started it moves very slowly for a few 
inches, as only the water that leaks by the automatic stop- 
valve is available to move it, but as the movement of the 



JSteam Engineering 



J 




FIG. 411 



High Pressure Elevators 67 

crosshead also operates the valve, the opening of the latter 
is rapidly increased and the car speed correspondingly ac- 
celerated. 

When the bar E has carried the stop N as far as the 
stop T the releasing lever S strikes the latter and the hook 
on the stop X is raised so that the bar E may slide by and 
leave the stop N adjoining the stop T, ready to be struck 
by the bar E on the next stroke. The actuating stops T 
are not held on the rod L but on a rod directly in front 
of it (see Fig. 410), and this rod is secured, so it will 
not move endwise, in the frame V. 

Fig. 411 shows a double-deck arrangement of two sepa- 
rate machines. This grouping of horizontal elevator en- 
gines is often resorted to for the purpose of economizing 
space, the machinery for operating two cars occupying the 
same floor area as that ordinarily required for one. 

High Pressure Elevators. The types of elevators hither- 
to discussed belong in the low pressure class, the water 
pressures used in operating them not exceeding 200 Ibs. per 
square inch, the average being about 150 Ibs. But the 
increase in the height of modern office buildings, and the 
demand for a high car speed have resulted in the develop- 
ment of high pressure elevators, operating under pressures 
as high as 700 Ibs. per square inch, and even higher in 
some cases. 

The reduction in the size of the machine and piping 
that can be effected by using this pressure is much greater 
than would be supposed by those who have not investigated 
the subject. To give a general idea of how great the re- 
duction actually is, suppose a low-pressure elevator has 
a cylinder 16 inches in diameter and works with a pres- 
sure of 100 pounds. For such a machine the supply pipe 
would probably be not less than 6 inches in diameter. Sub- 



fi8 Steam Engineering 

stitute for this a high-pressure machine working with 800 
pounds pressure per square inch; then, if everything el^e 
remains unchanged, the area of the cylinder will be re- 
duced to one-eighth, and this will make the diameter a 
trifle under 5% inches, as compared with the low-pressure 
cylinder of 16 inches diameter. This is not all the gain 
that can be made; there can also be effected a great re- 
duction in the size of the supply pipe, for as only one- 
eighth of the quantity of water is required, the size of the 
pipe can be reduced to the same degree as that of the cylin- 
der, provided the water is to run through it at the same 
velocity. This reduction would cut the pipe down from 
6 inches to a trifle over 2 inches in diameter. 

These reductions are not exactly what would be made in 
actual practice, because the frictional loss in the small 
high-pressure cylinder would not be as great as in the 
large low-pressure cylinder, and the velocity of the water 
through the supply pipe could be made greater for the 
same percentage of loss; this would permit a farther re- 
duction in the size of the pipe. In practice the gain in 
this direction is utilized in part to reduce the size of the 
apparatus, and in part to reduce the loss of energy in forc- 
ing the water through the pipes. As a result, the loss of 
energy due to the friction of the water passing through 
the pipes, lifting cylinder and valves is reduced to about 
5 or 6 per cent, whereas in low-pressure machines it run? 
from, say, 10 to 30 per cent. The change of pressure 
from 100 to 700 or 800 pounds brings about other changes 
in the construction of the machine and apparatus and also 
in the general arrangement of the system. 

The arrangement of the various parts of a high-pressure 
system is indicated by the diagram, Fig. 412. This dia- 
gram shows a machine geared six to one. The cylinder is 



High Pressure Elevators 



(10 



shown at C, the plunger at P and the traveling sheaves 
below it; the cylinder is inverted, the plunger being forced 
downward by the pressure of the water. This construe- 




Fro. 412 



tion is used because the small size of the cylinder makes 
it impracticable to use a piston and piston-rod, therefore 
a solid plunger is provided and the pressure acts to push 
it out of the cylinder. 



70 Steam Engineering 

In Fig. 412 the pump forces water into the lower end 
of the accumulator, from which a pipe runs to the ijiaiii 
valve, through which it passes to the pipe A and thence 
to the lifting cylinder. On the return stroke the water 
passes out of the cylinder through the pipe A and through 
the upper end of the main valve to the discharge pipe, 
which runs up to a tank placed on or near the roof of -the 
building. The object of this arrangement is to provide 
a low pressure to operate the pilot valve, which is shown 
in the diagram just above the main valve. In the first 
high-pressure elevators made, the pilot valve was operated 
with water at the same pressure that was used for the lift- 
ing cylinder, but these valves were not successful, owing to 
the fact that they had to be very small and the packings 
would not withstand the wear due to the pinhead jets of 
water striking them at terrific velocities; in addition, the 
small holes through which the water passed were soon en- 
larged so that the valve would not work satisfactorily. 
With the low-pressure pilot valve there is no trouble. A 
small tank is provided to receive the discharge from the 
pilot valve and its actuating cylinder, and this water is 
returned to the roof tank by means of a small pump as 
shown in Fig. 412. 

The Accumulator. The accumulator takes the place of 
the pressure tank of the low-pressure system. A pressure 
tank cannot be used with the high-pressure system, owing 
to the fact that it is troublesome and expensive to pump air 
against a high pressure, and it is necessary to do this so 
as to replenish the air that gradually leaks out of the pres- 
sure tank. Even if there were no difficulty in pumping air 
into a high-pressure tank, the accumulator would be pref- 
erable, because with it the pressure depends upon the 
weight on top of the plunger, not on the height of the 



The Accumulator 



71 



water in the cylinder. With a pressure tank the pressure 
drops as soon as water is drawn out, and it runs up as 
soon as the outflow stops, consequently the pressure is con- 
tinually varying. 




FIG. 413 



The arrangement of the entire apparatus of an Otis high- 
pressure vertical elevator is shown in Fig. 413. This il- 
lustration shows several parts not represented in. the ele- 
mentary diagram, Fig. 412. The main pump is at A and 



72 Steam. Engineering 

at B is shown the prime mover, which in this case is an 
electric motor, although in practice steam power is almost 
always used. The accumulator is shown at C and the 
main valve, and pilot valve are at D. From the main 
valve the water passes to the lifting cylinder through pipe 
E, passing first through an automatic stop-valve F, thence 
through pipe G to cylinder H. The plunger is shown at 
I, and the traveling sheaves at J. 

The high-pressure water from the accumulator reaches 
the main valve through pipe K and is discharged from the 
valve through pipe L which runs up to the tank at the 
top of the building. Through pipe M, the water returns 
to the pump A. An air chamber is provided at Q to 
smooth out any pulsations of the pump that its own air 
chamber does not subdue! The small pump to return the 
water discharged from the pilot valve to the roof tank is 
also shown. 

It will be noticed in Fig. 413 that the machine proper 
of a vertical high-pressure elevator is not very elaborate. 

Fig. 414 shows a sectional, and also a plan view of the 
main and pilot valves. 

The pilot valve is at A, and the main valve at C ; B is 
a motor cylinder, the piston of which moves the main 
valve. In this construction, the pilot valve is not much 
smaller in diameter than the main valve, and the motor 
piston is very much larger than the main valve. The dif- 
ference in the proportions of these parts as compared with 
the valves described in connection with low-pressure ma- 
chines is due to the fact that in the high-pressure system 
the motor piston is actuated by low-pressure water, so as 
to make it possible to use a pilot valve of large enough 
size to be durable. As is shown in Fig. -413, the tank into 
which the lifting cylinder discharges is placed high enough 



The Accumulator 



73 



to give enough pressure to operate the motor piston, and 
from this tank water passes through the pilot valve A to 
the cylinder B. If the motor piston were operated hy 
the high-pressure water, the pilot valve and its port holes 
would have to be so small that the parts could not be made 
sufficiently substantial. For this reason water at a pres- 




FIG. 414 

sure of about 80 pounds per square inch is used to operate 
the motor piston. 

It might be thought that having to discharge the water 
in the lifting cylinder against a back pressure of 80 pounds 
would cause considerable loss, and make the high-pressure 
system objectionable on the score of low efficiency, but this 
is not the case because the main pump draws water from 



74 Steam Engineering 

this same discharge tank; therefore, the back pressure 
against the lifting cylinder acts to help the pump, so that 
in reality all the work the pump has to do is to force water 
against a pressure equal to the difference between the pres- 
sure of the accumulator and that of the discharge tank. 
The net result is that if the accumulator pressure is 750 
pounds, and that of the discharge tank is 80 pounds, the 
actual pressure against which the pump acts is 750 80 
=670 pounds, and the pressure that acts in the lifting 
cylinder to raise the elevator car is 670 pounds, not taking 
into account the losses due to friction of the water through 
the pipes and valves on its way from the accumulator to 
the Cylinder. 

Operation of Main and Pilot Valves. The operation 
of the main and pilot valva in Fig. 414 is as follows: If 
the operator desires to run the car upward he moves the 
car lever so as to pull up the rope N' on the right side, 
thus tilting the rock lever N in a counter-clockwise direc- 
tion. The levers N and L are secured to the shaft P; 
hence, the end of L will move down and through the con- 
necting rod L' will pull down the lever L" ; and the latter, 
through M, will depress the pilot valve. The center pipe 
E is connected with the upper discharge tank : hence, water 
will flow in and through the lower end of the pilot-valve 
chamber, pass to the lower end of the motor-piston cylin- 
der B, and raise the piston, the water above the latter pass- 
ing out into the pilot-valve chamber above the valve, and 
thence to the pipe D. As the motor-piston rod is connected 
at both ends by arms J J with the ends of the main valve 
C, the upward . movement of the piston will lift the main 
valve, and then the water from the accumulator coming 
through the pipe I will pass into the center of the main 
valve through the port S. The port Q will be above the 



Cylinder and Plunger 75 

packing R, so that the water will pass out into the cen- 
tral pipe H and thence to the lifting cylinder, and by 
pushing the plunger out of the latter will lift the elevator 
car. If the rock lever N is tilted in the opposite direction, 
the pilot valve will be raised, and then water will pass to 
the upper end of the motor cylinder and depress the pis- 
ton, thus moving the main valve down so that the water 
in the lifting cylinder may escape through the ports Q' 
into the upper end of the main valve and thence through 
the ports S' to the upper discharge pipe G ; from there it 
passes to the discharge tank near the top of the building. 

Cylinder and Plunger. Figs. 415 and 416 show the 
construction of the plunger, cylinder, and sheaves of the 
Otis high pressure vertical cylinder elevator. 

Fig. 415 gives external and sectional views of the cylin- 
der, the upper end of which is seen at A and the lower 
end at B. To shorten up the drawing the cylinder is 
broken at C C. The plunger is indicated by D. Above 
the cylinder are shown the stationary sheaves held between 
side frames made of channel iron G, to the lower end of 
which the cylinder is bolted, as shown at G'. The channel 
frames G are bolted to a rod H at the upper end, and 
this is held between beams I that are secured to the wall 
or floor framing of the building. The traveling sheaves 
are carried in a crosshead attached to the lower end F of 
the plunger. 

The internal construction of the cylinder is shown in 
the vertical section, which is taken at right angles to the 
exterior view. The upper end of this drawing shows the 
way in which the bearings of the stationary sheaves are 
held between the side frame channel beams G G, and in 
like manner the lower end shows the construction of the 
cap F that forms the end of the plunger and the support 




Steam Engineering 



FIG. 415 




for the traveling-sheave frame. This cap is constructed 
cup-shaped on its upper side to receive the drip from the 



Cylinder and Plunger 77 

cylinder. The plunger, it will be noticed, does not fit the 
cylinder throughout its entire length, but only for a short 
distance at the lower end, where the stuffing-box is lo- 
cated. The cylinder is held up by the rod H, and is sus- 
tained against side displacement by means of one or more 
rings K and the frame J, the construction of both of which 
can be readily understood from the drawings. 

The outlet M in Fig. 415 is the pipe connection through 
which the actuating water enters and passes out of the 
cylinder. T-bars I' I' to which the frame J is bolted 
form the guides for the crosshead of the traveling sheaves, 
and the cylinder is held true with these by means of the 
frame J so as to keep the plunger and the crosshead guides 
in line. 

Fig. 416 shows side, and edge views of the crosshead, 
the guides, and the traveling sheaves. 

Fig. 417 shows the speed regulator used in connection 
with the Otis high pressure type of elevator. This device 
will not allow the car to attain an excessively high speed 
under any conditions, for the reason that it depends for 
its action upon the velocity of the current of water passing 
through it, and not upon the pressure. The device is con- 
nected in 'the piping so that the water that flows into or 
out of the lifting cylinder passes through it. If, when 
the car is ascending, the water enters through port, 0, and 
passes out through D, then on the descending trip the 
water will enter through D and pass out through C. In 
either case, the water will have to pass through the open- 
ings, E, in the valve piston, this passage causing a cer- 
tain amount of loss in pressure dependent entirely upon 
the velocity of the water through the holes, E. 

Suppose that, when the car is running at 400 feet per 
minute, the loss of pressure suffered by the water in 



78 



Steam Engineering 




FIG. 417 



passing through the piston holes, E, is 20 pounds; then, 
if the car is running up, and the pressure of the water 
when it reaches one side of B is 800 pounds, it will be, on 



Cylinder and Plunger 79 

the other side, 780 pounds. If the car is running down 
and the water is discharging into the delivery tank, a pres- 
sure of 100 pounds on the cylinder side of B will corre- 
spond to 80 pounds on the tank side of B; that is to say, 
in either case the difference in pressure between the two 
sides of B will be 20 pounds. 

From the construction of the device, it will be seen that 
the force with which the piston rod, A, is moved endwise by 
the difference in the pressure on the opposite sides of B 
is resisted by the spring, K, so that by properly adjusting 
this spring, the car can be made to run at any desired 
speed with the main valve wide open, regardless of the 
magnitude of the load or whether it is running up or 
down. Thus it will be seen that, when this speed regulator 
is provided, the car cannot attain an excessive velocity, 
even if the operator becomes confused and opens the main 
valve too wide. 

In passing from either of the inlets, C or P, into the 
interior of the cylinder, the water must flow through the 
small holes in the casing, F. These holes are drilled on 
spiral lines so that, when B moves in either direction, it 
covers the holes one at a time, thus gradually closing the 
outlet. The end movement of B is transmitted to one, or 
the other of the levers, G, through rod, A, and the move- 
ment of either lever will compress spring, K. 

Direct Acting Plunger Type. A direct acting plunger 
elevator consists of a cylinder set vertically in the ground 
directly under the car, and of length a few feet greater 
than the travel of the elevator car. In this cylinder is a 
plunger of the same length, carrying a car on its upper 
end. The bottom of the plunger is supported by an in- 
compressible body of water, and the car cannot descend 
faster than the water is forced out. 



80 



Steam Engineering 




FIG. 418 
DIRECT ACTING PLUNGER ELEVATOB 



Direct Acting Plunger Type 81 

The success of this elevator depends largely upon the 
merits of the operating mechanism. In the installation of 
this type of hydraulic elevator it is necessary to sink the 
hole for the reception of the cylinder to a depth equal 
to the height of the building. Fig. 418 shows the- general 
arrangement of the Otis direct acting plunger elevator. 
This illustration is broken at a point between the elevator 
car and the bottom of the elevator shaft in order to reduce 
its length, but the part broken away would only show the 
continuation of the guides, plunger, operating ropes, etc.; 
all the operating parts of the outfit are shown in the 
illustration. 

In plunger elevators, as the full pressure on the end of 
the plunger acts to lift the car, the diameter of the plunger 
is much smaller than in the geared types of elevators. The 
pressure used varies from about 140, to 200 pounds per 
square inch and the diameter of .the plunger may be from 
5 to 7 inches. The cj'linder is made of steel pipe about 
2 inches larger in diameter than the plunger, and the 
hole in the ground is a couple of inches larger than the 
cylinder. It will thus be seen that the hole in which the 
cylinder is placed is not very large, so that it can be bored 
in a manner similar to that employed for driving pipe 
wells. If the subsoil is earth, a steel pipe lining is pro- 
vided which is large enough to receive the cylinder. If 
the hole is drilled in rock, no lining is required. 

For the cylinder, a number of lengths of steel pipe are 
turned true on the ends, threaded in a lathe, and joined 
by sleeve couplings. The upper end of the cylinder is 
screwed into a cast-iron section which is bored to fit the 
plunger, and is provided with a stuffing-box and a pipe 
connection through which the water enters and passes out 
of the cylinder. The lower end of the cylinder is closed 



82 Steam Engineering 

by means of a suitable cap. The cylinder is coated with 
a protecting paint and when in position, the space between 
it and the sides of the hole is filled with sand. 

For the plunger, a number of lengths of steel pipe are 
turned true and well polished. The sections are joined by 
means of long internal sleeves which are so proportioned 
that the transverse strength of the plunger at the joint is 
as strong as at any other point. 

As the elevator car can rise only as high as the plunger 
travels, it follows that when the rise is 300 feet, the cylin- 
der must extend down into the earth several feet more 
than 300, because when the car is at the top of the elevator 
hatchway the bottom end of the plunger must be some dis- 
tance below the top end of the cylinder. Furthermore, it 
is necessary to provide sufficient length of plunger to carry 
the car a short distance above the upper floor, say, two 
feet, in order to avoid running the- bottom of the plunger 
too high up in the cylinder if the elevator should overrun 
the upper limit of travel. 

The plunger passes through a stuffing-box at the upper 
end of the cylinder, and is provided with guide shoes at 
the lower end to keep it in line and central. 

Referring to Fig. 418, the car rests upon the upper end 
of the plunger P, and the latter runs down into the cylin- 
der C, the upper end of which projects above the ground 
floor. From the top of the car a number of cables R ex- 
tend upward and over a sheave S and thence down to a 
counterbalance W. This counterbalance serves to reduce 
the pressure required to raise the elevator, and also to 
reduce the compression stress to which the plunger is 
subjected. 

The pipe of which the plunger is made weighs about 22 
pounds per foot, so that a plunger 200 feet long will weigh 



Direct Acting Plunger Type 83 

about 4,400 pounds; this is more than the car is likely 
to weigh, the latter ranging between 3,000 and 4,000 
pounds. If the car weighs, say, 3,600 pounds, and the 
plunger 4,400 pounds, the two combined will weigh 8,000 
pounds, and with no counterbalance this weight would have 
to be raised in addition to the load. Consequently the 
plunger would be subjected to a compression stress of 3,600 
pounds plus the load at the upper end, and 8,000 pounds 
plus the load at the bottom, the stress increasing from top 
downward at the rate of 22 pounds per foot. With a coun- 
terbalance weighing 5,000 pounds, the weight raised will 
be reduced to 3,000 pounds plus the load, and as the coun- 
terbalance exceeds the weight of the car by 1,400 pounds, 
it will actually hold up about one-third of the plunger, 
from the upper end downward, when the car is empty. 

When the car is at the bottom of the shaft the plunger 
is immersed in the water in the cylinder, consequently 
a portion of its weight is balanced by the water it dis- 
places. When the car is at the top of the shaft the 
plunger is out in the air and its weight is not counter- 
balanced to any extent by the water. This being the case, 
the weight lifted will be less when the car is at the bottom 
of its travel than when at the top, the difference being equal 
to the weight of water displaced by the plunger. By prop- 
erly proportioning the weight of the cables E, the load 
lifted can be made equal at all points, for when the car i? 
at the bottom of the shaft these cables will hang above the 
car, and thus will offset a portion of the counterbalance 
W, while when the car is at the top of the shaft the cables 
will hang above the counterbalance W and balance a por- 
tion of the weight of the car. 

The main valve for controlling the movement of the 
car is shown at V, and the pilot valve at V. The two 



84 Steam Engineering 

valves A and B are the automatic stop or limit valves, A 
being the top limit and B the bottom. The valve A is 
actuated by the rope A" which pulls up the lever A' and 
thereby closes the valve. This rope moves the lever A' 
through the motion of the elevator car. Looking at the 
illustration, it will be seen that the rope A" runs over 
a sheave D mounted on top of the elevator car, and it can 
also be seen that when the car approaches the upper limit 
of travel, D begins to put a bend in A" and thereby draws 
up the lever A'; by the time the car reaches the upper 
floor, A' will be raised enough to close the valve A. By 
this arrangement the valve is closed gradually and the 
car is as gradually brought to a state of rest. 

The valve B is actuated by the rope B" in precisely the 
same manner that A is operated by the rope A". The rope 
B" passes over the stationary sheave D' and under the 
sheave D" located under the car, and when the latter de- 
scends near enough to the lower floor, the bend put in the 
rope B" by the sheave D" will raise the lever B' and grad- 
ually close the valve B. 

The pressure water enters through the valve A; hence, 
at the top landing the automatic stop arrests the movement 
of the car by shutting off the supply water. When the 
elevator car descends, the discharge water passes out 
through the valve B; hence, the bottom limit valve stops 
the descent of the car by stopping the escape of water 
from the cylinder. 

Construction of Cylinder. The construction of the upper 
end of the cylinder is shown in Fig. 419. This drawing, 
which is a vertical sectional elevation of the top of the 
cylinder and plunger, also shows the way in which the 
plunger is fastened to the under side of, the car, as well 
as the construction of the plunger. For the purpose of 



Cylinder Construction 



85 




FIG. 419 



86 Steam Engineering 

reinforcing the plunger, a steel cable B is strung inside 
both of its ends fastened to a pin A, located some distant 
below the center of the plunger, and the loop or bight, a 
the top of the plunger, is passed around a tightening bloc] 
; this block is arranged so as to be drawn up by the bolt 
0' to put the desired tension on the rope B. The plunge 
D is made of as many lengths of piping of the prope 
size as may be necessary, these being connected by mean 
of long internal sleeves C. The plunger sections are turne< 
true and highly polished, and the screw threads at th 
ends are made with great accuracy, so as to hold the sec 
tions in perfect alignment when connected. The thread 
are also made extra long, so that the joints may be a 
strong as the other parts of the pipe. For the purpose o 
making the pipe sections come together perfectly centra 
when joined, the center portion of the sleeve is turned true 
and the ends of the pipe are bored to fit this portion ; whei 
the parts are screwed up, the turned central portion o 
the sleeve slides into the bored-out ends of the pipes am 
brings them into line, so that there is no point arouni 
the joint where one part projects over the other. 

The top of the cylinder is finished off with a casting 1 
screwed to the top of the upper section of the cylinde 
barrel E. On top of the cylinder cap F is mounted 
stuffing-box casting G, containing the usual packing spac 
T and fitted with a gland G'. The latter is constructei 
so as to form a space surrounding the plunger to hold oi 
which is fed in from the oil cup K. Above this oil reser 
voir is a recess in which babbitt metal wiping rings I ar 
placed for the purpose of scraping the oil off the plunge 
as it moves up, and retaining it in the space in gland G' 
In Fig. 418 it will be noticed that buffers F are provide! 
for the car to rest upon when at the lower floor. Simila 



Cylinder Construction 87 

buffers are also provided for the counterbalance W to rest 
upon, this to prevent running the car up against the over- 
head beams. The construction of the car buffers is shown 
in Fig. 420, which is an external view of the upper end of 
the cylinder taken at right angles to Fig. 419. The buffer 
consists of a plunger P made of pipe,' provided with a 




FIG. 420 

cast cap P' and a rubber cushion P". The plunger P 
slides within a cylinder C, also made of pipe. Within this 
cylinder there is a spring that is compressed by the plunger, 
the lower end of the latter being provided with a flat head 
to press against the top of the spring. The cylinder C is 
held in position by a side extension F, formed on the top 
cylinder casting F. The nuts F' F" are screwed on the 



88 Steam Engineering 

cylinder C, the latter being threaded, and by this means 
the height of the buffer is adjusted. To furnish additional 
support, so that the buffer may not be pushed down, and 
the thread of the nut F' stripped if the car should come 
down unusually hard, a pipe extension E is provided, ex- 
tending down to the . floor, or some other firm support. 
These buffers are set so as to be struck and compressed 
every time the car comes down to the lower floor, acting 
to stop the motion gradually. If the car descends at the 
normal speed, the buffer is compressed slightly, just a 
trifle more than is necessary to hold the unbalanced por- 
tion of the weight of the car, but if the car speed in ap- 
proaching the floor is excessive, the buffers will be com- 
pressed farther, and the car will run a few inches below 
the floor. 

Boiler Power for Elevators. The following very able 
discussion of this subject is presented by Charles L. Hub- 
bard in Power: 

"The power necessary to operate an elevator depends 
upon its size, the method of construction and counterbal- 
ancing, the speed, and the efficiency. Placing these con- 
ditions in the form of an equation : 



H.P. 

eX 33,000 

in which 

W ^weight of live load, 
w=unbalanced weight of car, 
S= speed in feet per minute, 
e=efficiency. 

The elevators in most general use for passenger service 
are of the hydraulic and electric types; for freight work, 
some steam and belted elevators are in commission, the 



Boiler Power for Elevators 89 

latter being connected directly with the line shaft in shops 
and factories. The general method of computing the power 
is the same for both hydraulic and electric elevators, al- 
though they differ to some extent in detail, making it ad- 
visable to consider them separately. 

The live load for a passenger elevator is usually figured 
on a basis of from 60 to 80 pounds per square foot of floor 
space, and the weight of the elevator itself from 100 to 
125 pounds per square foot, which also includes the safety 
device. These figures will be found ample for cars of or- 
dinary construction, but may be exceeded somewhat in 
the case of metal cars of especially massive design. 

Hydraulic Elevators. It is common practice with ele- 
vators of this type to counterbalance up to about three- 
fourths of the weight of the car. The speed varies from, 
say 200, to 600 feet per minute, 400 feet being about the 
average for office buildings of medium size. The efficiency 
is in the vicinity of 60 per cent. 

In computing the boiler power, it is usually assumed 
that probably all of the elevators will not be running at 
one time at their maximum capacity; it must be remem- 
bered also that power is required only on the upward trip, 
as the weight of the car causes it to descend under the 
control of a suitable braking device. When there is no 
definite information at hand, it is customary to compute 
the power necessary to operate all of the elevators at one 
time under full load,' and base the boiler power on two- 
thirds of this result. 

Example. An office building has four hydraulic eleva- 
tors, each having a floor space of 30 square feet. What 
boiler power should be provided, using the following aver- 
age data : Live load, 70 pounds per square foot of floor 
space; weight of elevator, 100 pounds per square foot of 



90 Steam Engineering 

floor space; speed, 400 feet per minute; efficiency, 60 per 
cent; steam consumption of pumps, 65 pounds per hour 
per horse-power. 

From the foregoing, 

JF=30X70X 3=6300; 
W =30X 100X3X0.25=2250. 

Then for a continuous upward movement with a full load 
the required horse-power would be : 

(6300+2250) 400 

172 horse-power. 

0.60X33,000 

but, of course, under actual conditions one-half of the 
lime is occupied by the downward trips, and the power 
required is therefore only one-half of this, or 80 horse- 
power. Making allowance for stops at the various floors 
r.nd for the time that part of the elevators are idle, it 
may be assumed that it will be sufficient to provide for 70 
per cent of the full time, or 0.70X86=60 horse-power. 
The steam consumption under the conditions stated would 
be 60X65=3,900 pounds per hour. 

Assuming 30 pounds of steam per boiler horse-power, 
which may be taken with sufficient accuracy when the pres- 
sure and feed-water temperature are not given, the re- 
quired boiler horse-power will be 3,900-^30=130. The 
boiler horse-power required for running a pump is com- 
puted in a similar manner to that for an engine. 

The rating, or capacity of a pump, however, is usually 
expressed in gallons of water per minute raised to a given 
height, instead of horse-power, as in the case of an en- 
gine. 

The weight of water in pounds per minute multiplied 
by the height in feet to which it is raised, divided by 
33,000. will give tV.e ireful, or delivered work of the pump 



Boiler Power for Elevators 91 

in horse-power. The friction of the water flowing through 
the passages and valves is so great under ordinary working 
conditions that not much more than 50 per cent of the 
indicated horse-power of the steam cylinders is represented 
by the net useful work. This calls for a large amount of 
steam in proportion to the work done, as shown by the 
table herewith, which gives the average steam consumption 
of the ordinary duplex pump. 

TABLE SHOWING AVERAGE STEAM CONSUMPTION OF DUPLEX 
PUMPS. 

Pounds of Steam 

per hour 

Type of Pnmp per delivered 

horse-power 

Simple non-condensing 120 

Compound non-condensing 65 

Triple non-condensing 40 

High-duty non-condensing , 30 

The head against which a pump works is the vertical 
distance between the surface of the water in the suction 
reservoir and that in the discharge reservoir. If the 
pump is delivering against a pressure, as in feeding a 
boiler, the pressure may be reduced to "feet head," by 
dividing the pressure per square inch by 0.43. 

Electric Elevators. The type of electric elevators most- 
ly used is the drum. The speeds at which this type com- 
monly runs may be taken as 300 and 500 feet per minute, 
respectively, for single, and double-drum machines; for 
regular work, speeds above 400 feet are not usually found 
necessary for the average building. 

So far as the necessary power is concerned, the single 
drum and duplex machines may be considered together. 
The efficiency of the?e is ordinarily from 50 to 70 per 



92 Steam Engineering 

cent, although theoretically the former is the more efficient 
type. In practice it is not customary to count on much 
more than 50 per cent, which gives results on the side of 
safety. 

The method of balancing the electric elevators of the 
drum- type differs from that applied to the hydraulic, in 
that the entire weight of the car plus from 40 to 50 per 
cent of the maximum live load is counterbalanced. From 
this it is evident that with no load the power required to 
pull the car down is that necessary to raise the excess 
counter-weight, which may be taken as equal to one-half 
the maximum live load, and to overcome the friction of 
the machine. When the car is half loaded it is bal- 
anced, and the power required is that to overcome friction 
only. At full load the conditions are the same as for an 
empty car, except the power is required during the up- 
ward trip instead of the downward. It is evident that. 
power may be required for both the upward and downward 
trips, depending upon the number of people in the car, 
but it will never be as great at any one time as in the 
case of the hydraulic elevator. 

Example. Taking the same conditions as in the pre- 
ceding example, what boiler power will be required to 
operate electric elevators of the drum type, having an 
efficiency of 50 per cent and a speed of 300 feet per minute ? 

In this case u, the unbalanced weight of the car, disap- 
pears, and the maximum live load is equal to only one- 
half the weight of the people in the car, the other half 
being counter-balanced, so that: 

JF==30X70X3X0.5=3150 pounds, 
from which 

3150X300 _ 
H ' P ' 0.50X33,000 =57 ' 



Boiler Power for Elevators 93 

If the full load was carried on both upward and down- 
ward trips, or sufficient of it on the downward trip to 
overbalance the counter-weight and the friction of the car, 
the conditions would be the same as in the case of the 
hydraulic elevator, that is, power would only be required 
on the upward trip. 

This condition, however, does not hold, especially in the 
case of office buildings, where during the morning hours 
the maximum loads are on the upward trips, with empty 
or nearly empty cars coming down. Under these con- 
ditions the power is practically the same on both trips, 
owing to the necessity of raising the counter-weight when 
the car is descending. This makes it necessary to treat 
the problem the same as though the machine were raising 
a continuous load. 

Assuming, as before, that a certain amount of time is 
required for passengers to enter and leave the car, and 
that all of the cars will not be running at one time, we 
may take 70 per cent of the above, or 57X0. 7 =-10, as the 
maximum horse-power to be delivered continuously by the 
motor. 

Assuming efficiencies of 80, 90 and 85 per cent for the 
motor, generator and engine, respectively, the required 
indicated horse-power of the engine will be 

40 

1=62 horse-power. 

0.80X0.90X0.85 

The boiler power will, of course, depend upon the water 
rate of the engine. Assuming that a simple non-condens- 
ing engine is employed, requiring 30 pounds of steam per 
indicated horse-power per hour, the boiler power will be 
practically the same as that of the engine, that is, 82 
horse-power. The power required to operate duplex eleva- 



94 Steam Engineering 

tors is practically the same, except a higher speed may be 
allowed." 

The method of balancing a screw machine is practically 
the same as for the hydraulic type. The efficiency of this 
machine may be taken as about 70 per cent. The horse- 
power for driving elevators of this type is calculated the 
same as for the hydraulic, except for the higher efficiency. 
After the power of the motor has been computed, the 
boiler power may be determined as in the preceding ex- 
ample. 

Freight elevators are computed in the same way, except 
they are run at lower speeds, and are built especially to 
carry the desired load in each particular case. When ap- 
plying these methods of computation to any particular 
case, the engineer should obtain all the data possible 
regarding the type of machine to be used, the probable 
speed, efficiency, etc., before proceeding; but if any of 
the data are lacking, the average figures already given 
may be used with approximate results. 

QUESTIONS AND ANSWERS. 

661. What are the essential parts of the Otis traction 
elevator ? 

Am. A traction motor driving sheave, and a pair of 
electrically released brake shoes. 

662. What type of electric motor is used in the Otis 
t '-action elevator? 

Ans. A slow speed shunt-wound motor. 

663. What is the principal function of the armature 
shaft besides carrying the armature? 

Ans. To support the load, 

G64. How, then, is the drum, or sheave driven? 
Ans. By means of projecting arms from the armature, 
that engage with similar arms projecting from the drum. 



Questions and Answers 95 

665. Describe the system of safety devices with which 
this elevator is equipped ? 

Ans. There are two groups of switches located respec- 
tively at top and bottom of the shaft, each switch in series 
being opened one after the other by the car as it passes. 
This retards the speed and finally brings the car to stop, 
applying the brake, independent of the operator in car. 

666. Are there any other safeties besides this ? 

Ans. Yes speed governors, wedge clamps for gripping 
the guides, and potential switches. 

667. Describe in general terms the construction of the 
Otis geared traction elevator ? 

Ans. A multi-grooved driving sheave around whicli the 
cable works. The sheave is mounted upon a shaft driven 
by geared wheels actuated by a right and loft hand worm 
cut on the armature shaft. 

668. What advantage is gained by the use of the double 
screw, or worm ? 

Ans. The elimination of all end thrust. 

669. With what kind of brake is this machine equipped? 
Ans. A mechanically applied, and electrically released 

brake. 

670. What type of motor is used? 

Ans. Compound-wound speed 800 R. P. M. 

671. When is the series field of this motor used? 
Ans. Only at starting. 

672. Why? 

Ans. To obtain a highly saturated field in the shortest 
possible time. 

673. How is a gradual slowing down of speed of car 
obtained with this elevator? 

Ans. By throwing a low resistance field across the ar- 
mature, thus providing a dynamic brake action. 



96 Steam Engineering 

674. "What kind of current is used for operating elec- 
tric elevators? 

Ans. Either alternating, or. direct current. 

675. How is the transmission of current to the motor 
of an electric elevator controlled? 

Ans. By means of an electric magnet controller op- 
erated through the switch in the car. 

676. How may considerable power be wasted in the 
operation of electric elevators? 

Ans. By careless handling making unnecessary stops 
and starts, or too sudden stops or starts. 

677. Briefly, of what does the mechanism of a hydraulic 
elevator consist? 

Ans. A cylinder and piston with one or more rods con- 
nected to a crosshead which carries the sheaves over which 
run the lifting cables from which the car is suspended. 

678. What moves the piston? 

Ans. "Water under pressure admitted by means of suit- 
able valves causes the piston to move from one end of the 
cylinder to the other, and back again. 

679. How is this motion transmitted to the elevator 
car? 

Ans. By means of the sheaves mounted on the cross- 
head which carry the lifting cables. 

680. In what position is the cylinder placed ? 

Ans. Either vertical alongside the hatchway, or hori- 
zontal in the basement of the building. 

681. How are the valves of a hydraulic elevator op- 
erated ? 

Ans. In some cases by a hand rope passing through 
the car and over small sheaves at the top and bottom of 
the hatchway, and connected with the main valve in the 
basement. By pulling this rope down the valve is opened, 



Questions and Answers 97 

and the car will ascend, while pulling the rope up will 
cause the car to descend. 

682. What safety devices are attached to this type of 
elevator ? 

Ans. Two halls are attached to the hand rope, oue near 
the bottom, and the other near the top. These balls come 
in contact with the top, or bottom of the car, according 
as it is going up or coming down, and being carried along 
they, of course move the cable, thus actuating the valve, 
bringing the car to a stop. 

683. Is this device safe, and automatic? 
Ans. It is. 

684. Mention another safety device connected with 
hydraulic elevators. 

Ans. Safety clamps under the control of a speed limit 
centrifugal governor which causes the clamps to grip the 
guides and thus hold the car. 

685. How is this safety governor operated ? 

Ans. By means of a small cable connected with the car 
and moving with it, which passes over the sheave pulley 
of the governor. 

686. Why are some elevator pistons fitted with two pis- 
ton rods? 

Ans. To prevent the piston, and crosshead from turn- 
ing or twisting, and also to strengthen the construction. 

687. What other methods are used for manipulating 
the water valve, besides the one already described? 

Ans. Running ropes, and standing ropes, either of 
which may be operated by means of a lever,, or wheel in 
the car. 

688. Do these devices directly operate the main valve? 
Ans. No. They operate a small valve called the pilot 

valve. 

689. What is the function of the pilot valve? 



98 Steam Engineering 

Ans. When opened it admits the pressure water to a 
small cylinder with piston connected to the main valve 
stem. This actuates the main valve, which in turn, by its 
movement, closes the pilot valve. 

690. Upon what does the amount of opening given the 
pilot valve, and consequently the main valve depend? 

Ans. Fpon the distance the lever in the car is moved 
from central position. 

691. What is meant by central position of lever? 
Ans. That position in which there is no flow of water 

either into or out of the cylinder, and the car is moving 
only by its momentum. 

692. What is the result of moving the lever too quickly 
to central position when the car is moving at a high 
rate of speed? 

Ans. The motion of the car will be arrested with a 
sudden jerk. 

693. How many kinds of horizontal hydraulic elevators 
are in use? 

Ans. Two. One is the pushing, and the other the 
pulling type. 

694. Describe the action of the pushing type? 

Ans. The car being at the bottom, the pressure water 
is admitted behind the piston which then moves, pushing 
the crosshead and cable sheave and lifting the car. 

695. Describe the action of the pulling type? 
Ans. It is the opposite of that just described. 

696. Is there much difference in the valve mechanism 
of the horizontal, and vertical types of hydraulic elevators ? 

Ans. Very little except a few minor details. 

697. What is meant by a double-deck machine? 

Ans. Where the floor space is restricted two, and some- 
times three or four machines are mounted one above the 
. other. 



Question* and Answers 99 

698. What water pressure is usually carried in operat- 
ing the types of hydraulic elevators that have hitherto 
been described? 

Ans. Pressures not exceeding 200 Ibs., the average being 
150 Ibs. per square inch. 

699. Are any higher pressures than this being used for 
operating hydraulic elevators? 

Ans. Yes. Pressures of 700 to 800 Ibs. and higher. 

700. Why are such high pressures used? 

Ans. Owing to increased height of buildings, and the 
demand for high car speed. 

701. What advantage, other than high speed, is gained 
by the use of high pressure elevators? 

Ans. A reduction in the size of the valve mechanism, 
piston areas and piping. 

702. Mention another advantage in connection with 
the high pressure system? 

Ans. A reduction in the loss by friction of the water 
passing through the pipes, owing to reduced areas. 

703. What is the percentage of loss due to this cause? 
Ans. In low pressure machines from 10 to 30 per 

cent, and in high pressure machines from 5 to 6 per cent. 

704. Describe in general terms the construction of the 
cylinder and piston of a high pressure machine. 

Ans. The cylinder area is reduced to about one-eighth 
that of the low pressure type, and the piston is a solid 
plunger. 

705. How is the pressure maintained? 

Ans. The pump forces water into the lower end of the 
accumulator, an air-tight tank, which is also weighted. 
From the accumulator a pipe runs to the main valve. 

706. Describe in general terms the construction and 
operation of the direct-acting plunger elevator. 



100 Steam Engineering 

Ans. A cylinder is set vertically in the ground under 
the center of the car, and the length of it is slightly 
greater than the travel of the car. In this cylinder is a 
plunger of the same length, which carries the car. Water 
under pressure is forced into the cylinder and thus lifts 
the car, and allowed to run out at the top when the car 
descends. The cylinder is about two inches larger in dia- 
meter than the plunger, and is always full of water. 

707. What is the usual diameter of the plunger? 
Ans. G!/> to 7 inches. 

708. How is it constructed? 

Ans. Of lengths of highl} r polished steel pipe, joined 
together with an internal sleeve, and having its lower end 
closed. 

709. What pressure is ordinarily used on this type of 
elevator ? 

Ans. 150 to 200 Ibs. per square inch. 

710. How is the top of the cylinder arranged ? 

Ans. With a packing gland through which the plunger 
moves up and down. 

711. What types of elevators are in general ue for 
passenger service? 

Ans. Electric and hydraulic. 

712. How is the capacity of a pump usually expressed? 
Ans. *In gallons of water per minute raised to a given 

height. 

713. What is meant by the head under which a pump 
works ? 

Ans. The vertical distance between the surface of the 
water in the suction reservoir, and that in the discharge 
reservoir. 



INDEX 

A 

Accumulator , 70-72 

Advantages of High Pressure Elevators 67-G8 

Alternating Current Machines 19 

Armature Shaft 11 

B 

Boiler House Power for Elevators 88-94 

Brake Shoes 18 

C 

Car and Counterbalance 16 

Careless Operation 21-2(3 

Cost of 22 

Dangers connected with 20 

Circulating Pipe 46 

Controlling Equipment 13-14 

Counterbalancing 13 

Cross Head 77 

Cylinder and Plunger 75-79 

D 

Direct Acting Plunger Elevator 79-88 

Construction of cylinder , .84-87 

Construction of plunger 81-82 

Installation of 80-81 

Principles of .79, 81-83 

Double Decked Machines 61-63 

Double Screw Machine 16-17 

Driving Cables 12-13 

E 
Electric Elevators . ,..11-22 



ii Index 

F 
Freight Elevators 94 

G 
Governor Types of 31-30 

H 

Hand Rope Control 2S-29 

High Pressure Elevators c7-7!> 

Action of water in 70-72 

Accumulator 70-74 

Advantages C7-CS 

Arrangements of parts t:S-70 

Cylinder and plunger 7.V79 

Pilot valve 72-7.". 

Horizontal Cylinder Type .".">-( '7 

Details of operation nc-rvr 

General arrangement ">-~t"t 

Pulling type fi7 

Pushing type 27-2S 

Horse Power required Electric Elevator 1)1-94 

Rules for calculating 93 

Hydraulic Elevators 2:5-S8 

General principle of 20-28 

L 

Lever Car Switch 21 

Low Pressure Vertical Cylinder Type . .2s-."> 

Governor for 31-3'J 

Hand rope control 2S-29 

Operating valve ; 23, 30-43 

Safety devices for 31 

Speed limit 29-30 

M 

Main Valve 74-75 

Method of Stopping IS 

Morse Williams & Co's Elevators 01-07 

Double decked machines 01-03 

Operation described 63-04 



Index iii 

Stop and main valves 64-67 

Motor for Electric Elevators 18 

O 

Oil Cushion Buffers . ; 14-15 

Operating Devices 47-55 

Operating Valve 27, 36-43 

Action of 38-40 

Description of parts 36-38 

For high speeds 36-43 

Otis Geared Traction Elevator 15-21 

Car and counterbalance 16 

Double screw machine 16-17 

Method of stopping 18 

Motor 18 

Traction principle 16 

Otis Traction Elevator 11-15 

Armature shaft 11 

Controlling equipment 11 

Counterbalancing 13 

Driving cables 12-13 

Slow speed motor 12 

Safety devices 15 

P 

Packing for Hydraulic Pistons 44 

Pistons for Hydraulic Elevators 44-46 

Piston Rods 46 

Pilot Valve 72-73 

Q 
Questions and Answers 94-100 

R 
Rules for Calculating Horse Power 93 

S 

Safeties 19-21 

Safety Devices 15, 31 

Shaft 18 

Slow Speed Motor 12 



iv Index, 

Speed Limit 29-3 

Speed Regulator Action of 77-7 

Steam Consumption Duplex Pumps 9 

Stop and Main Valves G4-0 

T 

Table of Currents and Fuse Capacity 2 

Traction Principle 1 



Twentieth Century 
Machine Shop Practice 

By L. ELLIOTT BROOKES 



The best and latest and most 
practical work published on mod- 
ern machine shop practice. This 
book is intended for the practical 
instruction of Machinists, Engin- 
eers and others who are interested 
in the use and operation of the 
machinery and machine tools in a 
modern machine shop. The first 
portion of the book is devoted to 
practical examples in Arithmetic, 
Decimal Fractions, Roots of Num- 
bers, Algebraic Signs and Symbols, 
Reciprocals and Logarithms of 
Numbers, Practical Geometry and 
and Mensuration. Also Applied 
Mechanics which includes: The 
lever, The wheel and pinion, The 
pulley, The inclined planes. The 
wedge The, screw and safety valve 
Specific gravity and the velocity 
of falling bodies Friction, Belt 
Pulleys and Gear wheels. 

Properties of steam. The Indi- 
cator, Horsepower and Electricity. 

Tb". latter part of the book gives full and complete information 
upon the fallowing subjects: Measuring devices. Machinists' tools. 
Shop tools. Machine tools. Boring machines, Boring mills, Drill 
presses, Gear Cutting machines. Grinding Machines, Lathes and Mill- 
ing machines. Also auxiliary mach ne tools, Portable tools, Miscella- 




neous tools. Plain and Spiral Index 



furnaces, Shop talks. Shop kinks, Medical Aid and over Fifty tabl 



The book is profusely illustra 



ng machines, Notes on Steel. Gas 



:ed and shows views of the latest 



sry and the most up-to-da 
driven machine tools, with full info 

tion. It has been the object of the author to presei 
matter in this work in as simple and not technical 
possible. 



e and improved belt and motor- 
mation as to their use and opera- 
the subject 
aimer as is 



12mo, cloth, 636 pages, 456 fine illustrations, price, $2.00 

Sold by Booksellers generally, or sent postpaid to 
any address upon receipt of Price by the Publishers 

FREDERICK J. DRAKE & CO. 

PUBLISHERS CHICAGO, U. S. A. 



THE KING OF ALL The Companion Volume to Modern 
Wiring Diagrams Just from the Press 

Electrical Wiring * 
Construction Tables 

By Henry C. Horstmann and Victor H. Tousley 

Contains hundreds of easy up-to-date tables covering everything on 

Electric Wiring. Bound in full Persian Morocco. 

Pocket size. Round corners, red edges. 

PRICE, MET, $1.50 

Partial Table of Contents 
This Book contains 

among others: 
Tables for direct current 

calculations. 

Tables for alternating cur- 
rent calculations. 
These tables show at a 
glance the currents re- 
quired with any of the 
systems in general use, 
fcr any voltage, effici- 
ency, or power-factor, 
and by a very simple 
calculation (which can 
be mentally made), also 
the proper wire for any 
less. 

Tables showing the small- 
est wire permissable 
with any system or num- 
ber of H. P. or lights 
under "National Electri- 
cal Code" or Chicago 
rules. Very convenient 
for contractors. 
Tables for calculating the 

most economical loss. 
Tables and diagrams 
showing proper size of 
conduits to accommo- 
date all necessary combinations or 
number of wires. 

Tables and data for estimating at a 
glance the quantity of material re- 
quired in different lines of work. 

AS this is intended for a pocket-hand-book everything that would 
makes it unnecessarily cumbersome is omitted. There is no 
padding. Every page is valuable and a time saver. This book will 
be used every day be the wireman, the contractor, engineer and 
architect. AH parts are so simple that ver? "'ttle electrical knowl- 
edge is required to understand them. 
Sint, all chrages paid to any address, ttpon receipt of price. 




FREDERICK J. DRAKE & CO., Publishers, 



Chicago 



The Practical Gas 
Oil Engine HAND-BOOK 








A MANUAL of useful in- 
*"* formation on the care, 
maintenance and repair of f^is 
and Oil Engines. 

This work gives full and 
clear instructions on all points 
relating to the care, mainte- 
nance and repair of Stationary. 
Portable and Marine, Gas and 
Oil Engines, including How to 
Start. How to Stop, How to Ad- 
just, How to Repair, How to 
Test. 

Pocket size, 4x6V4. Over 
200 pages. With numerous 
rules and formulas and dia- 
grams, and over 50 illustrations 
by L. ELLIOTT BROOKES, au- 
thor "f the "Construction of a 
Gasoline Motor," and the "Au- 
tomobile Hand-Book." 

This book has been written 
with the intention of furnishing 
practical information regarding 

gas, gasoline and kerosene engines, for the use of owners, operators and 

others who may be interested in their construction, operation and maa- 

agement. 

In treating the various subjects.it has been the endeavor to avoid all 

technical matter as far as possible, and to present the information given 

in a clear and practical manner. 

|6mo. Popular Edition Cloth. Price $1.00 

Edition de Luxe-Full Leather Limp. Price 1.56 

Sent Postpaid to any Address in the World upon Receipt of Price 

FREDERICK J. DRAKE & CO. 

PUBLISHERS 
CHICAGO, ILLINOIS. 



Easy Electrical Experiments 
and How to Make Them 

By L. P. DICKINSON 

This is the very latest and mosfj 
valuable work on Electricity for the 
amateur or practical Electrician pub- 
lished. It gives in a simple and 
easily understood language every 
thing you should know about Gal- 
vanometers, Batteries, Magnets, In- 
duction, Coils, Motors, Voltmeters, 
Dynamos, Storage Batteries, Simple 
and Practical Telephones, Telegraph 
Instruments, Rheostat, Condensers, Electrophorous, 
Resistance, Electro Plating, Electric Toy Making, etc. 
The book is an elementary hand book of lessons, 
experiments and inventions. It is a hand book for 
beginners, though it includes, as well, examples for 
the advanced students. The author stands second to 
none in the scientific world, and this exhaustive work 
will be found an invaluable assistant to either the 
Student or mechanic. 

Illustrated with hundreds of fine drawings; printed 
on a superior quality of paper. 

J2mo Cloth. Price, $J.25, 

Sent postpaid to any address upon receipt of prio 

^REDERICK J. DRAKE & CO.. Publishers^ 

CHICAGO, ILL. 




DYNAMO TENDING 



ENGINEERS 




Or, ELECTRICITY 
FOR STEAM ENGINEERS 

Sy HE3STRY C. KOESTMANN and 

VICTOR H. TOUSLEY, 
Authors of "Modern Wiring Diagrams and 
Descriptions for Electrical Workers." 



This excellent treatise is written by 
engineers for engineers, and is a clear 
and comprehensive treatise on the prin- 
ciples, construction and operation of 
Dynamos, Motors, Lamps, Storage Bat- 
teries, Indicators and Measuring Instru- 
ments, as well as full explanations of the 
principles governing the generation 
of alternating currents and a descrip- 
tion of alternating current instruments and machinery. There are 
perhaps but few engineers who have not in the course of their labors 
come In contact with the electrical apparatus sucli as pertains to light 
and power distribution and generation. it the present rate of increase 
In the use of Electricity it is but a question of time when every steam 
Installation will have in connecton with it an electrical generator, even 
In such buildings where light and power are supplied by some central 
station. It is essential that the man in charge of Engines, Boilers, 
Elevators, etc., be familiar with electrical matters, and it cannot well 
be other than an advantage to him and his employers. It is with a view 
to assisting engineers and others to obtain such knowledge as will enable 
them to intelligently manage such electrical apparatus as will ordinarily 
come under their control that this book has been written. The authors 
have had the co-operation of the best authorities, each in his chosen field, 
and the information given is just such as a steam engineer should know, 
To further this information, and to more carefully explain the text, 
nearly 100 illustrations are used, which, with perhaps a very few excep- 
tions, have been especially made for this book. There are many tables 
covering all sorts of electrical matters, so that immediate reference can 
be made without resorting to figuring. It covers the subject thoroughly, 
but so simply that any one can understand it fully. Any one making a 
prtense to electrical engineering needs this book. Nothing keeps a man 
down like the lack of training; nothing lifts him up as quickly or as 
surely as a thorough, practical knowledge of the work he has to do. This 
book was written for the man without an opportunity. No matter what 
he is, or what work he has to do, it gives mm just such information 
and training as are required to attain success. It teaches just what 
the steam engineer should know in his engine room about electricity. 
13mo, Cloth, 100 Illustrations. 8ize5^x7^. PRICE NET *l ffk 
Sold by booksellers generally, or sent, all charges paid, upon Ql i vU 
receipt of price ' 

FREDERICK J. DRAKE & CO., Publishers 

CHICAGO, ILL. 



COMPLETE EXAMINATION 
QUESTIONS AND ANSWERS 

FOR MARINE AND 
STATIONARY ENGINEERS 



> 



By Calvin F. Swingle, M. E. Author of Swingle's Twentieth 
Century Hand Book for Steam Engineers and Electricians. 
Modern Locomotive Engineering Handy Book, and 
Steam Boilers Their construction, care and management 

TjTHIS book is a compendium of 
^ useful knowledge, and prac- 
tical pointers, for all engineers, 
whether in the marine, or station- 
ary service. For busy men and tor 
those who are not inclined to snend 
any more time at study than is ab- 
solutely necessary, the book will 
prove a rich mine from which they 
may draw nuggets of just the kind 
of information that they are look- 
ing for. 

The meihod pursued by the au- 
thor in the compilation of the work 
and in the arrangement of the sub- 
ject matter, is such that a man in 

formation relative to the operation 
of his steam or electric plant, will 
experience no trouble in finding 
that particular item, and he will not 
be under the necessity of going 
over a couple of hundred pages, 
either, before he finds it because 
the matter i s systematically ar- 
ranged and classified. 

The book will be a valuable addition to any engineer's library, not 
alone as a convenient reference book, but also as a book for study. It 

pages fully illustrated, durably bound in full Persian Morocco limp, 
round corners, red edges. 

PRICE $1.50 

N. B. This is the very latest and best book on the subject in prim. 

(Sold by Booksellers generally or sent postpaid to 
any address upon receipt of price by the Publishers 
FREDERICK J. DRAKE & CO. 
CHICAGO. U. S. A. 




MODERN ELECTRICAL 
CONSTRUCTION 

By HORSTMANN and TOUSLEY 

7TTHIS book treats almost entirely of practical electrical 
^ work. It uses the ' 'Rules and Requirements of the Na- 
tional Board of Fire Underwriters" as a text, and ex- 
plains by numerous cuts and detailed explanations just how 
the best class of electrical 
work is installed. 

It is a perfect guide for 
the beginning electrician 
and gives him all the 
theory needed in practical 
work in addition to full 
practical instructions. For 
the journeyman electrician 
it is no less valuable, be- 
cause it elaborates and 
explains safety rules in 
vogue throughout the 
United States. It is also 

^E^tvAjrMyjkTw^^^^yo.jL^Tj'wiTyj of especial value to elec- 
uic-l inspectors, as it 

g ^JaSd 7 !^ u h n e 

scrupulous persons in the 
trade. 

The book also contains a 
number of tables giving di- 
mensions and trade num- 
bers of screws, nails, in- 
sulators and other material 
in general use, which will be found of great value in practice. 
There is also given a method by which the diameter of con- 
duit necessary for any number of wires of any size can be at 
once determined. The motto of the authors, "To omit noth- 
ing that is needed and include nothing that is not needed, " 
that has made "Wiring diagrams and Descriptions" so suc- 
cessful, has been followed in this work. No book of greater 
value to the man who does the work has ever been published. 
16mo, 250 pages, 100 diagrams. Full leather, limp. 
i- Price, net, ft. SO 

Sent postpaid to any address in the world upon receipt of priss 

FREDERICK J. DRAKE & CO. 




PUBLISHERS 



CHICAGO, 



ILLINOIS. 



The Calculation of Horse 
Power Made Easy : : : 

By L. ELLIOTT BROOKES 

Author of "Gas and Oil Engine Hand-Book," 
"The Automobile Hand-Book," Etc. 

Size, 5x7%. 80 Pages, Illustrated. Cloth, 75 Cents 



THIS work deals in a practical and non- 
technical manner with the calculation 
of the power of Steam Engines, *Explo- 
sive and Electric Motors. 

Particular attention has been given to the 
full explanation of the elementary principles 
upon which the calculations are based. 

It has been the endeavor to present in as 
simple a manner as is possible, a number of 
useful rules and formulas that may be of 
great value to ENGINEERS, MACHINISTS and 
DESIGNERS in calculating horse power. 

Rules for plotting steam engine diagrams 
by arithmetical, geometrical and graphical 
methods are given and fully explained, also 
the method used in plotting the diagram of 
an explosive motor. 

This work covers many points regarding 
the calculation of horse power and useful 
information not hitherto published in a single 

volume, and includes Calculated, Brake and Indicated horse power, Point of 
cut-off and average steam pressure, Horse Power of Explosive Motors, Degree 
of Compression and Combustion Chamber Dimensions, Indicator Diagrams of 
Steam Engines and Explosive Motors, also tables of Average Steam Pressure, 
Areas of Circles, Squares of Diameters of Circles, Natural Logarithms of Num- 
bers, Thermo-dynamic Properties of Gasoline and Air, Common Logarithms 
of Numbers, and Mensuration of Surface and Volume. 




The term " Explosive Motor" includes Gas, Gasoline and Oil Engines. 



SENT POSTPAID TO ANY ADDRESS IN 
THE WORLD UPON RECEIPT OF PRICE 

FREDERICK J. DRAKE & CO. 

PUBLISHERS 
PUBLISHERS. CHICAGO, ILL. 



Practical Mechanical Drawing 
and Machine Design Self-Taught 

By CHARLES WESTINGHOUSE 
Over 200 Illustrations and 160 Pages. Price, $2 00 




A COMPLETE SELF -INSTRUCTOR FOR HOME 
STUDY on Drafting tools Geometrical defini- 
tion of plane figures Properties of the circle Poly- 
gons Geometrical definitions of solids Geometrical 
drawing Geometrical problems Mensuration of plane 
surfaces Mensuration of volume and surface of solids 
The development of curves The development of sur- 
faces The intersection of surfaces Machine drawing 
Technical definitions Material used in machine con- 
struction Shafting Machine design Transmission of 
motion by belts Horsepower transmitted by ropes 
Horsepower of gears Transmission of motion by gears 
Diametral pitch system of gears Worm gearing 
Steam boilers Steam engines Tables. 

Frederick J. Drake & Co., Publishers 

CHICAGO, U. S. A. 



Practical Armature 
and Magnet Winding 

By HENRY C. HOUSTMANN and VICTOR H. TOUSLEY 



w 






P HILE the subject of armature wind- 
ing has, in the past, been more or 
less completely covered, most of 
these works have been either too technical 
in their composition or have required a 
fair degree of knowledge of the subject 
before they could be clearly understood. 
There has been a need of a book cover- 
ing this matter which, while giving all that 
is necessary for an intelligent under- 
standing, would, at the same time, present 
the matter in such a simple form that it 
could be readily grasped by those who 
had not had the benefit of a previous 
education along this line. 

This book treats in a practical and con- 
cise manner this very important subject. 

All practical armature windings are fully explained with special atten- 
tion paid to details. All questions which are apt to arise in the minds 
of the students have been completely answered. 

Numerous illustrations have been supplied, and these, taken in con- 
junction with the text, afford a ready means for either the study of the 
armature or f6r a book of reference. 

It has been the aim of the authors to supply all the necessary informa- 
tion required by the subject and, at the same time, to give this informa- 
tion in as condensed and brief a form as is consistent with a clear 
understanding. 

Various useful tables have been especially prepared for this work and 
these will not only reduce to a minimum the number of calculations re- 
quired, but lessen the possibility of errors. 

A chapter on the calculation of armatures gives complete information 
in detail for the design of an armature. 

Sold by booksellers generally or sent postpaid to any address upon receipt of price. 
16mo., Pocket Size, Full Persian Morocco Leather, Round 
Corners, Red Edges - $1.50 

FREDERICK J. DRAKE & CO. 

PUBLISHERS .... CHICAGO, ILLINOIS 



OPERATORS' WIRELESS TELEGRAPH 
AND TELEPHONE HAND-BOOK 



By VICTOR H. LAUGHTER 




TP-TO-DATE and most com- 



plete treatise on the subject 
yet published. Gives the 
historical work of early investi- 
gators on up to the present day. 
Describes in detail the construc- 
tion of an experimental wireless 
set. How to wind spark coil and 
dimensions of all size coils. The 
tuning of a wireless station is 
fully explained with points on 
the construction of the various 
instruments. 

A special chapter on the study 
of wireless telegraphy is given 
and the rules of the Naval sta- 
tions with all codes, abbrevia- 
tions, etc., and other matter in- 
teresting to one who takes up this study. 

The most difficult points have been explained in non- 
technical language and can be understood by the layman. 
Wireless telephony is given several chapters and all the 
systems in use are shown with photographs and drawings. 
By some practical work and a close study of this treatise 
one can soon master all the details of wireless telegraphy. 



Sold by booksellers generally or sent postpaid to any address upon receipt of price. 
12mo., Cloth, 210 Pages, Fully Illustrated, and with Six 
additional Full-Page Halftone Illustrations Showing the In- 
stallation of "Wireless" on the U. S. War Ships and Ocean 
Liners $1.00 



FREDERICK J. DRAKE & CO. 



PUBLISHERS 



CHICAGO, ILLINOIS 



ELEMENTARY ELECTRICITY 

UP TO DATE 

By SIDNEY AYLMER-SMALL, M. A. I. E. E. 




THIS book opens up the way for 
anyone who desires an accurate 
and complete knowledge of elec- 
tricity as a useful agent, in the hands 
of man, for the transmission of me- 
chanical energy, and the creation of 
light. 

In addition to opening up the way 
as referred to above, the book also 
serves as a guide and instructor to the 
seeker after knowledge along these 
lines. 

Beginning in the form of a simple 
catechism on the primary aspects of 
the subject it conducts the student by 
easy stages through the various as- 
pects of static electricity, the different 
types of apparatus for producing it, 
all of which are plainly described and 
illustrated and their action made plain and easy of comprehension. 
Quite a large space is devoted to this important topic, although no 
more than is actually necessary, as the subjects of condensers and simple 
electrical machines are also thoroughly handled, and the principles 
governing their action clearly explained and illustrated. The subject of 
atmospheric electricity is next dealt with, and lightning arresters treated 
upon, especially in their relation to electric power stations, sub-stations 
and line wires. The wonderful and mysterious subject of magnetism 
is next treated upon at length and clearly explained the explanations 
being accompanied by illustrations. 

Primary batteries of all types, storage batteries and the effects of elec- 
trolysis each and all receive a large share of attention. Electric circuits 
and the laws governing the flow of current, including Ohm's law, are all 
clearly explained. The student has now arrived at the point where 
electrical work, power and efficiency is the topic, and where the genera- 
tion and transmission of electrical currents of high potential and large 
volume are explained. 

Sold by booksellers generally or sent postpaid to any address upon receipt of price. 
12mo. Cloth, 500 Pages, Fully Illustrated : Price, $1.00 



FREDERICK J. DRAKE & CO. 



PUBLISHERS 



CHICAGO, ILLINOIS 






University of California 
SOUTHERN REGIONAL I 



. LIBRARY FACILITY 
405 Hilgard Avenue, Los Angeles, CA 90024-1388 
Return this material to the library 
from which it was borrowed. 



2 WEEK 




OC1 



_ -URL 
OV 10 



31991 



A 000 351 062 5 



